feat : EventDetails : Back button + read more option

lib/ui/views/event_details/event_details_viewmodel.dart

@@ -1,6 +1,10 @@
+import 'package:bahla_front/app/app.locator.dart';
 import 'package:stacked/stacked.dart';
+import 'package:stacked_services/stacked_services.dart';
 
 class EventDetailsViewModel extends BaseViewModel {
+  final _navigationService = locator<NavigationService>();
+
   int _selectedTabIndex = 0;
   
   int get selectedTabIndex => _selectedTabIndex;
@@ -9,6 +13,13 @@ class EventDetailsViewModel extends BaseViewModel {
     _selectedTabIndex = index;
     notifyListeners();
   }
+
+  void onBackPressed() {
+    // Handle back button press logic here
+    print('Back button pressed');
+    _navigationService.back();
+  }
+
 }
 
 class Post {