feat(neon_notifications): disable button when no notifications

Signed-off-by: Sanskar2807 <Sanskar2807@gmail.com>

packages/neon/neon_notifications/lib/pages/main.dart

@@ -28,12 +28,16 @@ class _NotificationsMainPageState extends State<NotificationsMainPage> {
         stream: bloc.notifications,
         builder: (final context, final notifications) => Scaffold(
           resizeToAvoidBottomInset: false,
-          floatingActionButton: FloatingActionButton(
+          floatingActionButton: StreamBuilder<int>(
-            onPressed: () async {
+            stream: bloc.unreadCounter,
-              bloc.deleteAllNotifications();
+            builder: (final context, final snapshot) {
-            },
+              final unreadCount = snapshot.data ?? 0;
+              return FloatingActionButton(
+                onPressed: unreadCount > 0 ? bloc.deleteAllNotifications : null,
                 tooltip: AppLocalizations.of(context).notificationsDismissAll,
                 child: const Icon(MdiIcons.checkAll),
+              );
+            },
           ),
           body: NeonListView(
             scrollKey: 'notifications-notifications',