[ML] Add data-test-subj to some job management elements (#35284) (#35456)

Backports the following commits to 7.0:
- [ML] Add data-test-subj to some job management elements (#35284)

x-pack/plugins/ml/public/jobs/jobs_list/components/delete_job_modal/delete_job_modal.js

@@ -109,6 +109,7 @@ export const DeleteJobModal = injectI18n(class extends Component {
       modal = (
         <EuiOverlayMask>
           <EuiConfirmModal
+            data-test-subj="mlDeleteJobConfirmModal"
             ref={this.setEL}
             title={title}
             onCancel={this.closeModal}

x-pack/plugins/ml/public/jobs/jobs_list/components/job_filter_bar/job_filter_bar.js

@@ -136,7 +136,7 @@ class JobFilterBarUI extends Component {
 
     return (
       <EuiFlexGroup direction="column">
-        <EuiFlexItem grow={false}>
+        <EuiFlexItem data-test-subj="mlJobListSearchBar" grow={false}>
           <EuiSearchBar
             box={{
               incremental: true,

x-pack/plugins/ml/public/jobs/jobs_list/components/jobs_list/jobs_list.js

@@ -255,6 +255,7 @@ class JobsListUI extends Component {
 
     return (
       <EuiBasicTable
+        data-test-subj="mlJobListTable"
         loading={loading === true}
         noItemsMessage={loading ?
           intl.formatMessage({

x-pack/plugins/ml/public/jobs/jobs_list/components/new_job_button/new_job_button.js

@@ -24,6 +24,7 @@ export function NewJobButton() {
   const buttonEnabled = (checkPermission('canCreateJob') && mlNodesAvailable());
   return (
     <EuiButton
+      data-test-subj="mlCreateNewJobButton"
       onClick={newJob}
       size="s"
       disabled={(buttonEnabled === false)}

x-pack/plugins/ml/public/jobs/jobs_list/components/refresh_jobs_list_button/refresh_jobs_list_button.js

@@ -17,6 +17,7 @@ import { FormattedMessage } from '@kbn/i18n/react';
 
 export const RefreshJobsListButton = ({ onRefreshClick, isRefreshing }) => (
   <EuiButtonEmpty
+    data-test-subj="mlRefreshJobListButton"
     onClick={onRefreshClick}
     isLoading={isRefreshing}
   >