[UnifiedDocViewer] Move Discover doc viewer into plugin/package (#162847)

## Summary

Replaces https://github.com/elastic/kibana/pull/154012.

Moves the Discover doc viewer component into a new plugin/package,
`@kbn/unified-doc-viewer` and `@kbn/unified-doc-viewer-plugin`.

### Checklist

- [ ] Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/packages/kbn-i18n/README.md)
- [ ]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [ ] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [ ] Any UI touched in this PR is usable by keyboard only (learn more
about [keyboard accessibility](https://webaim.org/techniques/keyboard/))
- [ ] Any UI touched in this PR does not create any new axe failures
(run axe in browser:
[FF](https://addons.mozilla.org/en-US/firefox/addon/axe-devtools/),
[Chrome](https://chrome.google.com/webstore/detail/axe-web-accessibility-tes/lhdoppojpmngadmnindnejefpokejbdd?hl=en-US))
- [ ] If a plugin configuration key changed, check if it needs to be
allowlisted in the cloud and added to the [docker
list](https://github.com/elastic/kibana/blob/main/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker)
- [ ] This renders correctly on smaller devices using a responsive
layout. (You can test this [in your
browser](https://www.browserstack.com/guide/responsive-testing-on-local-server))
- [ ] This was checked for [cross-browser
compatibility](https://www.elastic.co/support/matrix#matrix_browsers)

### Risk Matrix

Before closing this PR, invite QA, stakeholders, and other developers to
identify risks that should be tested prior to the change/feature
release.

When forming the risk matrix, consider some of the following examples
and how they may potentially impact the change:

| Risk | Probability | Severity | Mitigation/Notes |

|---------------------------|-------------|----------|-------------------------|
| Multiple Spaces—unexpected behavior in non-default Kibana Space.
| Low | High | Integration tests will verify that all features are still
supported in non-default Kibana Space and when user switches between
spaces. |
| Multiple nodes—Elasticsearch polling might have race conditions
when multiple Kibana nodes are polling for the same tasks. | High | Low
| Tasks are idempotent, so executing them multiple times will not result
in logical error, but will degrade performance. To test for this case we
add plenty of unit tests around this logic and document manual testing
procedure. |
| Code should gracefully handle cases when feature X or plugin Y are
disabled. | Medium | High | Unit tests will verify that any feature flag
or plugin combination still results in our service operational. |
| [See more potential risk
examples](https://github.com/elastic/kibana/blob/main/RISK_MATRIX.mdx) |

### For maintainers

- [ ] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>
Co-authored-by: Shahzad <shahzad31comp@gmail.com>

examples/unified_doc_viewer/README.md

@@ -0,0 +1,3 @@
+## Unified Doc Viewer
+
+An example plugin showing usage of the unified doc viewer plugin (plugins/unified_doc_viewer) and package (@kbn/unified-doc-viewer).

examples/unified_doc_viewer/kibana.jsonc

@@ -0,0 +1,16 @@
+{
+  "type": "plugin",
+  "id": "@kbn/unified-doc-viewer-examples",
+  "owner": "@elastic/kibana-core",
+  "description": "Examples showing usage of the unified doc viewer.",
+  "plugin": {
+    "id": "unifiedDocViewerExamples",
+    "server": false,
+    "browser": true,
+    "requiredPlugins": [
+      "data",
+      "developerExamples",
+      "unifiedDocViewer"
+    ]
+  }
+}

examples/unified_doc_viewer/public/application.tsx

@@ -0,0 +1,72 @@
+/*
+ * 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 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import React, { useEffect, useState } from 'react';
+import ReactDOM from 'react-dom';
+import type { AppMountParameters, CoreStart } from '@kbn/core/public';
+import { buildDataTableRecord } from '@kbn/discover-utils';
+import type { DataTableRecord } from '@kbn/discover-utils/types';
+import type { DataView } from '@kbn/data-views-plugin/common';
+import { UnifiedDocViewer } from '@kbn/unified-doc-viewer-plugin/public';
+import { DataPublicPluginStart } from '@kbn/data-plugin/public';
+import type { StartDeps } from './plugin';
+
+export const renderApp = (
+  core: CoreStart,
+  { data }: StartDeps,
+  { element }: AppMountParameters
+) => {
+  ReactDOM.render(<UnifiedDocViewerExamplesApp data={data} />, element);
+
+  return () => {
+    ReactDOM.unmountComponentAtNode(element);
+  };
+};
+
+function UnifiedDocViewerExamplesApp({ data }: { data: DataPublicPluginStart }) {
+  const [dataView, setDataView] = useState<DataView | null>();
+  const [hit, setHit] = useState<DataTableRecord | null>();
+
+  useEffect(() => {
+    data.dataViews.getDefault().then((defaultDataView) => setDataView(defaultDataView));
+  }, [data]);
+
+  useEffect(() => {
+    const setDefaultHit = async () => {
+      if (!dataView?.id) return;
+      const response = await data.search
+        .search({
+          params: {
+            index: dataView?.getIndexPattern(),
+            body: {
+              fields: ['*'],
+              _source: false,
+            },
+          },
+        })
+        .toPromise();
+      const docs = response?.rawResponse?.hits?.hits ?? [];
+      if (docs.length > 0) {
+        const record = buildDataTableRecord(docs[0], dataView);
+        setHit(record);
+      }
+    };
+
+    setDefaultHit();
+  }, [data, dataView]);
+
+  return (
+    <>
+      {dataView?.id && hit ? (
+        <UnifiedDocViewer hit={hit} dataView={dataView} />
+      ) : (
+        'Loading... (make sure you have a default data view and at least one matching document)'
+      )}
+    </>
+  );
+}

examples/unified_doc_viewer/public/index.ts

@@ -0,0 +1,12 @@
+/*
+ * 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 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+import { UnifiedDocViewerExamplesPlugin } from './plugin';
+
+export function plugin() {
+  return new UnifiedDocViewerExamplesPlugin();
+}

examples/unified_doc_viewer/public/plugin.tsx

@@ -0,0 +1,49 @@
+/*
+ * 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 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+import { AppMountParameters, CoreSetup, CoreStart, Plugin } from '@kbn/core/public';
+import { DeveloperExamplesSetup } from '@kbn/developer-examples-plugin/public';
+import type { DataPublicPluginStart } from '@kbn/data-plugin/public';
+
+export interface SetupDeps {
+  developerExamples: DeveloperExamplesSetup;
+}
+
+export interface StartDeps {
+  data: DataPublicPluginStart;
+}
+
+export class UnifiedDocViewerExamplesPlugin implements Plugin<void, void, SetupDeps, StartDeps> {
+  public setup(core: CoreSetup<StartDeps>, deps: SetupDeps) {
+    // Register an application into the side navigation menu
+    core.application.register({
+      id: 'unifiedDocViewer',
+      title: 'Unified Doc Viewer Examples',
+      async mount(params: AppMountParameters) {
+        // Load application bundle
+        const { renderApp } = await import('./application');
+        // Get start services as specified in kibana.json
+        const [coreStart, depsStart] = await core.getStartServices();
+        // Render the application
+        return renderApp(coreStart, depsStart, params);
+      },
+    });
+
+    // This section is only needed to get this example plugin to show up in our Developer Examples.
+    deps.developerExamples.register({
+      appId: 'unifiedDocViewer',
+      title: 'Unified Doc Viewer Examples',
+      description: 'Examples showcasing the unified doc viewer.',
+    });
+  }
+
+  public start(core: CoreStart) {
+    return {};
+  }
+
+  public stop() {}
+}

examples/unified_doc_viewer/tsconfig.json

@@ -0,0 +1,24 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "target/types"
+  },
+  "include": [
+    "index.ts",
+    "common/**/*.ts",
+    "public/**/*.ts",
+    "public/**/*.tsx",
+    "../../typings/**/*"
+  ],
+  "exclude": [
+    "target/**/*",
+  ],
+  "kbn_references": [
+    "@kbn/core",
+    "@kbn/data-plugin",
+    "@kbn/data-views-plugin",
+    "@kbn/developer-examples-plugin",
+    "@kbn/discover-utils",
+    "@kbn/unified-doc-viewer-plugin",
+  ]
+}