Implement UI for history visibility acknowledgement. (#31156)

* feat: Implement UI for history visibility acknowledgement.

Shows a banner above the message composer whenever a user opens a room
with non-join history visibility, which they can dismiss.

- Whenever a user opens an encrypted room with non-join history
  visibility, show them a banner, unless we have already marked it as
  dismissed.
- Whenever a user opens an encrypted room with joined history
  visibility, we unmark it as dismissed.

Issue: https://github.com/element-hq/element-meta/issues/2875

* tests: Add test suite for `RoomStatusBarHistoryVisible`.

* docs: Document `RoomStatusBarHistoryVisible` and props interface.

* feat: Use newer `@vector-im/compound` components.

* test: Update snapshots for `RoomStatusBarHistoryVisible` tests.

* chore: Update playwright screenshots.

* feat: Move `RoomStatusBarHistoryVisible` to `shared-components`.

* fix: Address review comments on `RoomStatusBarHistoryVisible`.

* fix: Address review comments on `RoomStatusBar` and tests.

* chore: Move `RoomStatusBarHistoryVisible` to `room/RoomStatusBarHistoryVisible`

* chore: Fix linting issues.

* feat: Gate behind history visibility labs flag.

* feat: Add link to history sharing docs.

* fix: Resolve build issue with shared-components.

* tests: Enable history sharing lab for unit tests.

* tests: Set labs flag in SettingsStore mock.

* fix: Remove non-existent arg - documentation should be updated!

* chore: Remove old CSS rule filter.

* fix: Use package name for import over relative path.

* fix: Mark styles as important due to improper CSS load order.

* docs: Add doc comments to `!important` directives.

This change should restore my status as a good person.

* docs: Correct license header.

* tests: Update `RoomStatusBarHistoryVisible` snapshot.

* tests: Update shared history invite screenshot.

* tests: Revert spurious screenshot changes.

* feat: Update to use `Banner` component.

* chore: Remove broken import.

* chore: Remove unused translation string.

* tests: Add `getHistoryVisibility` to `currentState` of stub room.

* tests: Update screenshot.

* chore: Remove old snapshots.

* tests: Update playwright screenshot.

* feat: Separate `HistoryVisibleBanner` hooks into MVVM architecture.

* chore: Remove unused imports.

* feat: Use info link over action button for `HistoryVisibleBanner`

* tests: Update snapshot for `HistoryVisibleBanner`.

* chore: Remove unused imports.

* feat: Switch to MVVM architecture per style guide.

* tests: Update snapshot for `HistoryVisibleBanner`.

* tests: Update shared components snapshots.

* tests: Add unit tests for `HistoryVisibleBannerView` stories.

* fix: Linting errors from SonarCloud.

* feat: Finalise conversion to MVVM.

* fix: Silent `this` binding issue.

* tests: Update playwright snapshot.

* feat: Introduce wrapper component for `HistoryVisibleBanner`.

* tests: Update playwright screenshots for `HistoryVisibleBanner`.

* docs: Add doc comments to fields in `HistoryVisibleBannerViewModel`.

* tests: Update playwright snapshot.

test/test-utils/test-utils.ts

@@ -9,6 +9,7 @@ Please see LICENSE files in the repository root for full details.
 import EventEmitter from "events";
 import { mocked, type MockedObject } from "jest-mock";
 import {
+    type EventTimeline,
     MatrixEvent,
     type Room,
     type User,
@@ -16,7 +17,6 @@ import {
     type IEvent,
     type RoomMember,
     type MatrixClient,
-    type EventTimeline,
     type RoomState,
     EventType,
     type IEventRelation,
@@ -30,6 +30,7 @@ import {
     JoinRule,
     type OidcClientConfig,
     type GroupCall,
+    HistoryVisibility,
 } from "matrix-js-sdk/src/matrix";
 import { KnownMembership } from "matrix-js-sdk/src/types";
 import { normalize } from "matrix-js-sdk/src/utils";
@@ -627,6 +628,7 @@ export function mkStubRoom(
         createThreadsTimelineSets: jest.fn().mockReturnValue(new Promise(() => {})),
         currentState: {
             getStateEvents: jest.fn((_type, key) => (key === undefined ? [] : null)),
+            getHistoryVisibility: jest.fn().mockReturnValue(HistoryVisibility.Joined),
             getMember: jest.fn(),
             mayClientSendStateEvent: jest.fn().mockReturnValue(true),
             maySendStateEvent: jest.fn().mockReturnValue(true),