test: remove default widget test

- Removed unnecessary test
- Cleaned up test directory

Author: fulleni

lib/bloc_observer.dart

@@ -16,4 +16,4 @@ class AppBlocObserver extends BlocObserver {
     log('onError(${bloc.runtimeType}, $error, $stackTrace)');
     super.onError(bloc, error, stackTrace);
   }
-}
+}