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/Mocks/SpaceServiceProxyMock.swift

@@ -5,6 +5,7 @@
 // Please see LICENSE files in the repository root for full details.
 //
 
+import Combine
 import Foundation
 import MatrixRustSDK
 
@@ -27,3 +28,16 @@ extension SpaceServiceProxyMock {
         }
     }
 }
+
+extension SpaceServiceProxyMock.Configuration {
+    static var populated: SpaceServiceProxyMock.Configuration {
+        let spaceRoomLists = [SpaceRoomProxyProtocol].mockJoinedSpaces.map {
+            ($0.id, SpaceRoomListProxyMock(.init(spaceRoomProxy: $0, initialSpaceRooms: .mockSpaceList)))
+        }
+        let subSpaceRoomLists = [SpaceRoomProxyProtocol].mockSpaceList.map {
+            ($0.id, SpaceRoomListProxyMock(.init(spaceRoomProxy: $0, initialSpaceRooms: .mockSingleRoom)))
+        }
+        
+        return .init(joinedSpaces: .mockJoinedSpaces, spaceRoomLists: .init(uniqueKeysWithValues: spaceRoomLists + subSpaceRoomLists))
+    }
+}