Fixes #978 - Message forwarding support

* Add support for message forwarding

* Move the TimelineProvider within the RoomProxy to avoid it going out of sync and have it automatically register for timeline updates on init

* Implement single selection form button style for message forwarding

* Add searching and filter out the source room from the list

* Fixed emoji screen initial search bar height

* Add view models tests

* Add changelog

* Update strings

* Tweaks following code review

ElementX/Sources/Screens/RoomDetailsScreen/RoomDetailsScreenViewModel.swift

@@ -89,13 +89,6 @@ class RoomDetailsScreenViewModel: RoomDetailsScreenViewModelType, RoomDetailsScr
     // MARK: - Private
 
     private func setupRoomSubscription() {
-        switch roomProxy.registerTimelineListenerIfNeeded() {
-        case .success, .failure(.roomListenerAlreadyRegistered):
-            break
-        case .failure:
-            MXLog.error("Failed to register a room listener in room's details for the room \(roomProxy.id)")
-        }
-        
         roomProxy.updatesPublisher
             .throttle(for: .milliseconds(200), scheduler: DispatchQueue.main, latest: true)
             .sink { [weak self] _ in