Add a banner to encrypted rooms with visible history. (#4851)

* Add a banner to encrypted rooms with visible history. (#4738)

* feat: Add history visible alert.

- Adds a dismissable alert that is displayed whenever the user
  opens a room with `history_visibility` != `joined`. When cleared,
  this is recorded in the app's data store.
- When opening a room with `history_visibility` = `joined`, this
  flag is cleared.

Issue: element-hq/element-meta#2875

* tests: Add unit tests for history sharing in `RoomScreenFooterView`.

* feat: Rename flag to `hasSeenHistoryVisibleBannerRooms`, document.

* refactor: Merge enum variants, use function for banner description.

* feat: Use `AppSettings.historyVisibleDetailsURL` over hard-coded value.

* tests: Correct potential race condition with deferred assertion.

* chore: Use Localazy translation string over project-defined.

* fix: Final tweaks and review comments.

* chore: Checkout `Enterprise` submodule.

* tests: Final fixes.

* fix: Condition banner visibility on feature flag state.

* fix: Prioritise identity violations over history visibility banner.

* tests: Add snapshots for history visible banner.

* tests: Use deferred failure timeout for improved test power.

* chore: Tweaks to spelling, simplify state logic.

* fix: Remove "g".

* fix: Show banner for shared/world-readable rooms, not invited.

* refactor: Use `else-if` instead of `if`.

ElementX/Sources/Application/Settings/AppSettings.swift

@@ -32,6 +32,7 @@ final class AppSettings {
         case seenInvites
         case hasSeenSpacesAnnouncement
         case hasSeenNewSoundBanner
+        case acknowledgedHistoryVisibleRooms
         case appLockNumberOfPINAttempts
         case appLockNumberOfBiometricAttempts
         case timelineStyle
@@ -173,6 +174,10 @@ final class AppSettings {
     @UserPreference(key: UserDefaultsKeys.hasSeenNewSoundBanner, defaultValue: true, storageType: .userDefaults(store))
     var hasSeenNewSoundBanner
     
+    /// The Set of room identifiers that the user has acknowledged have visible history.
+    @UserPreference(key: UserDefaultsKeys.acknowledgedHistoryVisibleRooms, defaultValue: [], storageType: .userDefaults(store))
+    var acknowledgedHistoryVisibleRooms: Set<String>
+    
     /// The initial set of account providers shown to the user in the authentication flow.
     ///
     /// Account provider is the friendly term for the server name. It should not contain an `https` prefix and should
@@ -206,7 +211,6 @@ final class AppSettings {
     private(set) var identityPinningViolationDetailsURL: URL = "https://element.io/help#encryption18"
     /// A URL describing how history sharing works
     private(set) var historySharingDetailsURL: URL = "https://element.io/en/help#e2ee-history-sharing"
-
     /// Any domains that Element web may be hosted on - used for handling links.
     private(set) var elementWebHosts = ["app.element.io", "staging.element.io", "develop.element.io"]
     /// The domain that account provisioning links will be hosted on - used for handling the links.