When joining room in sub-space join the parents too (#11011)

* When joining room in sub-space join the parents too

* Fix joined state not updating on sync

* Add membership check

* Update tests

* Improve coverage

* Make TS happier

* Make TS happier

test/test-utils/test-utils.ts

@@ -236,6 +236,7 @@ export function createTestClient(): MatrixClient {
 
         searchUserDirectory: jest.fn().mockResolvedValue({ limited: false, results: [] }),
         setDeviceVerified: jest.fn(),
+        joinRoom: jest.fn(),
     } as unknown as MatrixClient;
 
     client.reEmitter = new ReEmitter(client);