Promote "history sharing on invite" out of developer options (#5480)

* Enable key-share-on-invite irrespective of feature flag

* Remove feature-flag dep: warning on starting chat with new people

* Remove feature-flag dep: invite from room member details

* Remove feature-flag dep: warning on new users in invite screen

* Remove feature-flag dep: from room details screen

* Remove feature-flag dep: starting chat from user profile screen

* Remove feature-flag dep: timeline info on forwarded keys

* Remove feature-flag dep: RoomScreenModel

* Remove `enableKeyShareOnInvite` from AppSettings

* Remove `enableKeyShareOnInvite` feature flag

* Remove outdated comments

* Update preview test room snapshots as their header now includes the history sharing icon

ElementX/Sources/Services/UserSession/UserSessionStore.swift

@@ -136,7 +136,6 @@ class UserSessionStore: UserSessionStoreProtocol {
                          sessionDelegate: keychainController,
                          appHooks: appHooks,
                          enableOnlySignedDeviceIsolationMode: appSettings.enableOnlySignedDeviceIsolationMode,
-                         enableKeyShareOnInvite: appSettings.enableKeyShareOnInvite,
                          threadsEnabled: appSettings.threadsEnabled)
             .sqliteStore(config: .init(dataPath: credentials.restorationToken.sessionDirectories.dataPath,
                                        cachePath: credentials.restorationToken.sessionDirectories.cachePath)