Added markAll as read for notification

lib/data/repositories/notification_repository.dart

@@ -18,7 +18,8 @@ class NotificationsRepository {
     );
   }
 
-  Future<Result<NotificationResponseModel>> markAllAsRead() async {
-    return _notificationsService.markAllAsRead();
-  }
+Future<Result<Map<String, dynamic>>> markAllAsRead() async {
+  return _notificationsService.markAllAsRead();
+}
+
 }