Add room's update publisher (#952)

* Add room update publisher

* Cleanup

* Update room’s title

* Add refresh logic in RoomDetailsScreenViewModel

* Fix UTs

* Add UT

* Update timeline listener in RoomProxy

* Fix caching in LoadableAvatarImage

* Cleanup

* Update RoomProxy api

* Inject room proxy in RoomScreenViewModel

* Cleanup

* Fix UTs

ElementX/Sources/Services/Room/RoomProxyProtocol.swift

@@ -20,6 +20,7 @@ import MatrixRustSDK
 
 enum RoomProxyError: Error {
     case noMoreMessagesToBackPaginate
+    case roomListenerAlreadyRegistered
     case failedPaginatingBackwards
     case failedRetrievingMemberAvatarURL
     case failedRetrievingMemberDisplayName
@@ -59,14 +60,19 @@ protocol RoomProxyProtocol {
     var avatarURL: URL? { get }
 
     var membersPublisher: AnyPublisher<[RoomMemberProxyProtocol], Never> { get }
+    
+    /// Publishes the room's updates.
+    /// The publisher starts publishing after the first call to `registerTimelineListenerIfNeeded()`
+    /// The thread on which this publisher sends the output isn't defined.
+    var updatesPublisher: AnyPublisher<TimelineDiff, Never> { get }
 
     func loadAvatarURLForUserId(_ userId: String) async -> Result<URL?, RoomProxyError>
     
     func loadDisplayNameForUserId(_ userId: String) async -> Result<String?, RoomProxyError>
     
-    func addTimelineListener(listener: TimelineListener) -> Result<[TimelineItem], RoomProxyError>
-    
-    func removeTimelineListener()
+    /// Registers a timeline listener if not registered already.
+    /// Updates for this object will be published on the `updatesPublisher` publisher.
+    func registerTimelineListenerIfNeeded() -> Result<[TimelineItem], RoomProxyError>
     
     func paginateBackwards(requestSize: UInt, untilNumberOfItems: UInt) async -> Result<Void, RoomProxyError>
     
@@ -130,4 +136,10 @@ extension RoomProxyProtocol {
     func sendMessage(_ message: String) async -> Result<Void, RoomProxyError> {
         await sendMessage(message, inReplyTo: nil)
     }
+    
+    // Avoids to duplicate the same logic around in the app
+    // Probably this should be done in rust.
+    var roomTitle: String {
+        displayName ?? name ?? "Unknown room 💥"
+    }
 }