feat: Enhance trip management features and improve UI responsiveness

- Implemented AutomaticKeepAliveClientMixin in HomeContent to maintain state during navigation.
- Modified trip loading logic to trigger after the first frame for better performance.
- Updated trip loading events to use LoadTripsByUserId for consistency.
- Added temporary success messages for trip creation and operations.
- Improved UI elements for better user experience, including updated text styles and spacing.
- Refactored trip model to support Firestore timestamps and improved error handling during parsing.
- Streamlined trip repository methods for better clarity and performance.
- Enhanced trip service methods to ensure correct mapping from Firestore documents.
- Removed unnecessary trip reset logic on logout.

lib/main.dart

@@ -63,7 +63,7 @@ class MyApp extends StatelessWidget {
           ),
           BlocProvider(
             create: (context) =>
-                TripBloc(tripRepository: context.read<TripRepository>()),
+                TripBloc(context.read<TripRepository>()),
           ),
           BlocProvider(create: (context) => UserBloc()),
         ],