Space flow improvements. (#4430)

* Space flow improvements

- Use a state machine to select a space.
- Add a SpaceFlowCoordinator for recursively presenting subspaces.
- Get the spaceRoomListProxy when tapping on the space so we can indicate failures.
- Fix the total room count in SpaceListScreen.

* Refactor spaceRoom → spaceRoomProxy.

* Add a UI test for the Spaces flow.

ElementX/Sources/Services/Client/ClientProxy.swift

@@ -57,6 +57,8 @@ class ClientProxy: ClientProxyProtocol {
     
     private(set) var sessionVerificationController: SessionVerificationControllerProxyProtocol?
     
+    let spaceService: SpaceServiceProxyProtocol
+    
     private static var roomCreationPowerLevelOverrides: PowerLevels {
         .init(usersDefault: nil,
               eventsDefault: nil,
@@ -164,6 +166,10 @@ class ClientProxy: ClientProxyProtocol {
         
         secureBackupController = SecureBackupController(encryption: client.encryption())
         
+        // Temporarily using the mock until the SDK is updated.
+        // spaceService = SpaceServiceProxy(spaceService: client.spaceService())
+        spaceService = SpaceServiceProxyMock(.init())
+        
         let configuredAppService = try await ClientProxyServices(client: client,
                                                                  actionsSubject: actionsSubject,
                                                                  notificationSettings: notificationSettings,