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* Remove outdated comments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

UnitTests/Sources/StartChatViewModelTests.swift

@@ -89,7 +89,6 @@ struct StartChatScreenViewModelTests {
     
     @Test
     func inviteConfirmationFetchesIdentity() async throws {
-        ServiceLocator.shared.settings.enableKeyShareOnInvite = true
         clientProxy.directRoomForUserIDReturnValue = .success(nil)
         clientProxy.userIdentityForFallBackToServerReturnValue = .success(UserIdentityProxyMock(configuration: .init(verificationState: .notVerified)))
         
@@ -105,7 +104,6 @@ struct StartChatScreenViewModelTests {
     
     @Test
     func inviteConfirmationFallsBackToUnknownIdentityOnFailure() async throws {
-        ServiceLocator.shared.settings.enableKeyShareOnInvite = true
         clientProxy.directRoomForUserIDReturnValue = .success(nil)
         clientProxy.userIdentityForFallBackToServerReturnValue = .failure(.forbiddenAccess)