Added functionality to jump to talk-tab when app is launched via notification

lib/app.dart

@@ -23,12 +23,13 @@ import 'view/pages/timetable/timetable.dart';
 class App extends StatefulWidget {
   const App({Key? key}) : super(key: key);
 
+  static PersistentTabController bottomNavigator = PersistentTabController(initialIndex: 0);
+
   @override
   State<App> createState() => _AppState();
 }
 
 class _AppState extends State<App> {
-  int currentPage = 0;
   late Timer refetchChats;
   late Timer updateTimings;
 
@@ -68,11 +69,9 @@ class _AppState extends State<App> {
 
   @override
   Widget build(BuildContext context) {
-    PersistentTabController tabController = PersistentTabController(initialIndex: 0);
-
     return PersistentTabView(
       context,
-      controller: tabController,
+      controller: App.bottomNavigator,
       navBarStyle: NavBarStyle.style6,
       hideNavigationBarWhenKeyboardShows: true,
       navBarHeight: MediaQuery.of(context).viewInsets.bottom > 0 ? 0.0 : kBottomNavigationBarHeight,