#53 - Refactored various components:

- updated the authentication coordinator to use async await
- replaced the UserSession with a ClientProxy (similar to the RoomProxy)
- renamed `completion` to `callback` on the coordinators and view models
- renamed `viewModelResult` to `viewModelAction`
- introduced back UserSession as a user specific service container

ElementX/Sources/Screens/HomeScreen/HomeScreenViewModelProtocol.swift

@@ -19,11 +19,11 @@ import UIKit
 
 @MainActor
 protocol HomeScreenViewModelProtocol {
-    var completion: ((HomeScreenViewModelResult) -> Void)? { get set }
+    var callback: ((HomeScreenViewModelAction) -> Void)? { get set }
     
     var context: HomeScreenViewModelType.Context { get }
     
     func updateWithUserAvatar(_ avatar: UIImage)
     func updateWithUserDisplayName(_ displayName: String)
-    func updateWithRoomList(_ roomList: [RoomSummaryProtocol])
+    func updateWithRoomSummaries(_ roomSummaries: [RoomSummaryProtocol])
 }