[Fleet] Remove usage of deprecated component EuiPageContent_Deprecated (#162390)

Fixes https://github.com/elastic/kibana/issues/161418

## Summary
Removing usage of deprecated component `EuiPageContent_Deprecated` and
replacing with `EuiPageSection`.

Also removed two unused components.

The two components look like this:

<img width="1001" alt="Screenshot 2023-07-20 at 17 03 05"
src="82798d53-30ae-455b-b0fc-216461f8d1b8">

<img width="1683" alt="Screenshot 2023-07-24 at 11 02 57"
src="f6ca00a5-49b3-481e-9152-d1f2a77d4495">


To display them, I simply hardcoded `true`
[here](59450f0a22/x-pack/plugins/fleet/public/applications/fleet/sections/agents/index.tsx (L60))
and
[here](59450f0a22/x-pack/plugins/fleet/public/applications/fleet/sections/agents/index.tsx (L66))

---------

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/fleet/public/applications/fleet/sections/agents/agent_requirements_page/es_requirements_page.tsx

@@ -10,7 +10,7 @@ import { i18n } from '@kbn/i18n';
 import { FormattedMessage } from '@kbn/i18n-react';
 import {
   EuiPageBody,
-  EuiPageContent_Deprecated as EuiPageContent,
+  EuiPageSection,
   EuiText,
   EuiSpacer,
   EuiIcon,
@@ -22,6 +22,8 @@ import {
   EuiLink,
 } from '@elastic/eui';
 
+import styled from 'styled-components';
+
 import { WithoutHeaderLayout } from '../../../layouts';
 import type { GetFleetStatusResponse } from '../../../types';
 import { useStartServices } from '../../../hooks';
@@ -48,15 +50,21 @@ export const RequirementItem: React.FunctionComponent<{ isMissing: boolean }> =
   );
 };
 
+const borderColor = '#d3dae6';
+
+const StyledPageBody = styled(EuiPageBody)`
+  border: 1px solid ${borderColor};
+  border-radius: 5px;
+`;
+
 export const MissingESRequirementsPage: React.FunctionComponent<{
   missingRequirements: GetFleetStatusResponse['missing_requirements'];
 }> = ({ missingRequirements }) => {
   const { docLinks } = useStartServices();
-
   return (
     <WithoutHeaderLayout>
-      <EuiPageBody restrictWidth={820}>
-        <EuiPageContent hasBorder={true} hasShadow={false}>
+      <StyledPageBody restrictWidth={820}>
+        <EuiPageSection color="transparent">
           <EuiCallOut
             title={i18n.translate('xpack.fleet.setupPage.missingRequirementsCalloutTitle', {
               defaultMessage: 'Missing security requirements',
@@ -141,8 +149,8 @@ xpack.security.authc.api_key.enabled: true`}
               ),
             }}
           />
-        </EuiPageContent>
-      </EuiPageBody>
+        </EuiPageSection>
+      </StyledPageBody>
     </WithoutHeaderLayout>
   );
 };

x-pack/plugins/fleet/public/applications/fleet/sections/agents/error_pages/components/no_data_layout.tsx

@@ -5,36 +5,31 @@
  * 2.0.
  */
 
-import {
-  EuiEmptyPrompt,
-  EuiFlexGroup,
-  EuiFlexItem,
-  EuiPageContent_Deprecated as EuiPageContent,
-} from '@elastic/eui';
+import { EuiEmptyPrompt, EuiFlexGroup, EuiFlexItem, EuiPageSection } from '@elastic/eui';
 import React from 'react';
 import { withRouter } from 'react-router-dom';
 
 interface LayoutProps {
   title: string | React.ReactNode;
   actionSection?: React.ReactNode;
-  modalClosePath?: string;
 }
 
 export const NoDataLayout: React.FunctionComponent<LayoutProps> = withRouter<
   any,
   React.FunctionComponent<LayoutProps>
->(({ actionSection, title, modalClosePath, children }: React.PropsWithChildren<LayoutProps>) => {
+>(({ actionSection, title, children }: React.PropsWithChildren<LayoutProps>) => {
   return (
     <EuiFlexGroup justifyContent="spaceAround">
       <EuiFlexItem grow={false}>
-        <EuiPageContent>
+        <EuiPageSection color="transparent">
           <EuiEmptyPrompt
+            color="plain"
             iconType="logoBeats"
             title={<h2>{title}</h2>}
             body={children}
             actions={actionSection}
           />
-        </EuiPageContent>
+        </EuiPageSection>
       </EuiFlexItem>
     </EuiFlexGroup>
   );

x-pack/plugins/fleet/public/applications/fleet/sections/agents/error_pages/enforce_security.tsx

@@ -1,28 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License
- * 2.0; you may not use this file except in compliance with the Elastic License
- * 2.0.
- */
-
-import React from 'react';
-import { FormattedMessage, injectI18n } from '@kbn/i18n-react';
-
-import { NoDataLayout } from './components/no_data_layout';
-
-export const EnforceSecurityPage = injectI18n(({ intl }) => (
-  <NoDataLayout
-    title={intl.formatMessage({
-      id: 'xpack.fleet.disabledSecurityTitle',
-      defaultMessage: 'Security is not enabled',
-    })}
-    actionSection={[]}
-  >
-    <p>
-      <FormattedMessage
-        id="xpack.fleet.disabledSecurityDescription"
-        defaultMessage="You must enable security in Kibana and Elasticsearch to use Elastic Fleet."
-      />
-    </p>
-  </NoDataLayout>
-));

x-pack/plugins/fleet/public/applications/fleet/sections/agents/error_pages/invalid_license.tsx

@@ -1,29 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License
- * 2.0; you may not use this file except in compliance with the Elastic License
- * 2.0.
- */
-
-import React from 'react';
-import { FormattedMessage, injectI18n } from '@kbn/i18n-react';
-
-import { NoDataLayout } from './components/no_data_layout';
-
-export const InvalidLicensePage = injectI18n(({ intl }) => (
-  <NoDataLayout
-    title={intl.formatMessage({
-      id: 'xpack.fleet.invalidLicenseTitle',
-      defaultMessage: 'Expired license',
-    })}
-    actionSection={[]}
-  >
-    <p>
-      <FormattedMessage
-        id="xpack.fleet.invalidLicenseDescription"
-        defaultMessage="Your current license is expired. Enrolled Beats Agents will continue to work, but you need a valid
-          license to access the Elastic Fleet interface."
-      />
-    </p>
-  </NoDataLayout>
-));

x-pack/plugins/translations/translations/fr-FR.json

@@ -16371,8 +16371,6 @@
     "xpack.fleet.deletePackagePolicy.failureSingleNotificationTitle": "Erreur lors de la suppression de l'intégration \"{id}\"",
     "xpack.fleet.deletePackagePolicy.fatalErrorNotificationTitle": "Erreur lors de la suppression de l'intégration",
     "xpack.fleet.deletePackagePolicy.successSingleNotificationTitle": "L'intégration \"{id}\" a été supprimée",
-    "xpack.fleet.disabledSecurityDescription": "Vous devez activer Security dans Kibana et Elasticsearch pour utiliser Elastic Fleet.",
-    "xpack.fleet.disabledSecurityTitle": "La fonctionnalité Security n'est pas activée",
     "xpack.fleet.editAgentPolicy.cancelButtonText": "Annuler",
     "xpack.fleet.editAgentPolicy.devtoolsRequestDescription": "Cette requête Kibana met à jour une politique d'agent.",
     "xpack.fleet.editAgentPolicy.errorNotificationTitle": "Impossible de mettre à jour la stratégie d'agent",
@@ -16665,8 +16663,6 @@
     "xpack.fleet.integrations.updatePackage.upgradePoliciesCheckboxLabel": "Mettre à niveau les stratégies d'intégration",
     "xpack.fleet.integrationsAppTitle": "Intégrations",
     "xpack.fleet.integrationsHeaderTitle": "Intégrations",
-    "xpack.fleet.invalidLicenseDescription": "Votre licence actuelle a expiré. Les agents Beats enregistrés continuent à fonctionner, mais vous avez besoin d'une licence valide pour accéder à l'interface d'Elastic Fleet.",
-    "xpack.fleet.invalidLicenseTitle": "Licence expirée",
     "xpack.fleet.multiRowInput.addAnotherUrl": "Ajouter une autre URL",
     "xpack.fleet.multiRowInput.addRow": "Ajouter une ligne",
     "xpack.fleet.multiRowInput.deleteButton": "Supprimer la ligne",

x-pack/plugins/translations/translations/ja-JP.json

@@ -16384,8 +16384,6 @@
     "xpack.fleet.deletePackagePolicy.failureSingleNotificationTitle": "統合「{id}」の削除エラー",
     "xpack.fleet.deletePackagePolicy.fatalErrorNotificationTitle": "統合の削除エラー",
     "xpack.fleet.deletePackagePolicy.successSingleNotificationTitle": "統合「{id}」を削除しました",
-    "xpack.fleet.disabledSecurityDescription": "Elastic Fleet を使用するには、Kibana と Elasticsearch でセキュリティを有効にする必要があります。",
-    "xpack.fleet.disabledSecurityTitle": "セキュリティが有効ではありません",
     "xpack.fleet.editAgentPolicy.cancelButtonText": "キャンセル",
     "xpack.fleet.editAgentPolicy.devtoolsRequestDescription": "このKibanaリクエストにより、エージェントポリシーが更新されます。",
     "xpack.fleet.editAgentPolicy.errorNotificationTitle": "エージェントポリシーを更新できません",
@@ -16678,8 +16676,6 @@
     "xpack.fleet.integrations.updatePackage.upgradePoliciesCheckboxLabel": "統合ポリシーのアップグレード",
     "xpack.fleet.integrationsAppTitle": "統合",
     "xpack.fleet.integrationsHeaderTitle": "統合",
-    "xpack.fleet.invalidLicenseDescription": "現在のライセンスは期限切れです。登録されたビートエージェントは引き続き動作しますが、Elastic Fleetインターフェースにアクセスするには有効なライセンスが必要です。",
-    "xpack.fleet.invalidLicenseTitle": "ライセンスの期限切れ",
     "xpack.fleet.multiRowInput.addAnotherUrl": "別のURLを追加",
     "xpack.fleet.multiRowInput.addRow": "行の追加",
     "xpack.fleet.multiRowInput.deleteButton": "行の削除",

x-pack/plugins/translations/translations/zh-CN.json

@@ -16384,8 +16384,6 @@
     "xpack.fleet.deletePackagePolicy.failureSingleNotificationTitle": "删除集成“{id}”时出错",
     "xpack.fleet.deletePackagePolicy.fatalErrorNotificationTitle": "删除集成时出错",
     "xpack.fleet.deletePackagePolicy.successSingleNotificationTitle": "已删除集成“{id}”",
-    "xpack.fleet.disabledSecurityDescription": "必须在 Kibana 和 Elasticsearch 启用安全性，才能使用 Elastic Fleet。",
-    "xpack.fleet.disabledSecurityTitle": "安全性未启用",
     "xpack.fleet.editAgentPolicy.cancelButtonText": "取消",
     "xpack.fleet.editAgentPolicy.devtoolsRequestDescription": "此 Kibana 请求将更新代理策略。",
     "xpack.fleet.editAgentPolicy.errorNotificationTitle": "无法更新代理策略",
@@ -16678,8 +16676,6 @@
     "xpack.fleet.integrations.updatePackage.upgradePoliciesCheckboxLabel": "升级集成策略",
     "xpack.fleet.integrationsAppTitle": "集成",
     "xpack.fleet.integrationsHeaderTitle": "集成",
-    "xpack.fleet.invalidLicenseDescription": "您当前的许可证已过期。已注册 Beats 代理将继续工作，但您需要有效的许可证，才能访问 Elastic Fleet 界面。",
-    "xpack.fleet.invalidLicenseTitle": "已过期许可证",
     "xpack.fleet.multiRowInput.addAnotherUrl": "添加另一个 URL",
     "xpack.fleet.multiRowInput.addRow": "添加行",
     "xpack.fleet.multiRowInput.deleteButton": "删除行",