Fix login flow and room name updates

1. Logging in with saved credentials should
just go straight to rooms page without
flickering the login page
2. Rooms should be updated if an event
fires for their names changing

lib/main.dart

@@ -51,6 +51,10 @@ class _MyHomePageState extends State<MyHomePage> {
     if (!mounted) return;
     final provider = Provider.of<ZenithClientProvider>(context, listen: false);
     final client = Client("zenith");
+    provider.setClient(client);
+    setState(() {
+      showRooms = true;
+    });
 
     try {
       await client.checkHomeserver(Uri.parse(homeserver));
@@ -58,10 +62,6 @@ class _MyHomePageState extends State<MyHomePage> {
         await client.login(LoginType.mLoginPassword,
             password: password,
             identifier: AuthenticationUserIdentifier(user: username));
-      provider.setClient(client);
-      setState(() {
-        showRooms = true;
-      });
     } catch (error) {
       print(error);
       setState(() {
@@ -81,14 +81,14 @@ class _MyHomePageState extends State<MyHomePage> {
     if (errorMessage.isNotEmpty)
       return Column(
         children: [
-          ErrorWidget(errorMessage),
           ElevatedButton(
               onPressed: () {
                 setState(() {
                   errorMessage = "";
                 });
               },
-              child: const Text("Clear"))
+              child: const Text("Clear")),
+          ErrorWidget(errorMessage),
         ],
       );
     if (showRooms)

lib/rooms.dart

@@ -81,13 +81,13 @@ class _RoomsPageState extends State<RoomsPage> {
         padding: const EdgeInsets.all(16.0),
         child: Center(child: Consumer<ZenithClientProvider>(
           builder: (context, provider, child) {
-            provider.client.roomsLoading?.then((value) {
+            provider.client.onRoomState.stream.listen((event) {
               setState(() {
                 loadingRooms = false;
               });
             });
 
-            if (provider.client.roomsLoading != null && loadingRooms)
+            if (loadingRooms)
               return const CircularProgressIndicator();
             else
               return ListView.builder(