Show RoomList when cached state is loaded

This should somewhat speed up the loading since we don't need to wait
until the first sync is done.

It's still slow though since loading the cache is slow

src/controller.cpp

@@ -292,6 +292,9 @@ void Controller::invokeLogin()
                         setActiveConnection(connection);
                         connectSingleShot(connection, &Connection::syncDone, this, &Controller::initiated);
                     }
+                    if (!connection->nextBatchToken().isEmpty()) {
+                        Q_EMIT initiated();
+                    }
                 });
                 connect(connection, &Connection::loginError, this, [this, connection](const QString &error, const QString &) {
                     if (error == "Unrecognised access token") {