feat(content_management): add data update event for create source BLoC

- Implement CreateSourceDataUpdated event to update BLoC with shared data
- Add handler for CreateSourceDataUpdated event in CreateSourceBloc
- Update countries and languages in CreateSourceState using new event data

Author: fulleni

lib/content_management/bloc/create_source/create_source_bloc.dart

@@ -30,6 +30,7 @@ class CreateSourceBloc extends Bloc<CreateSourceEvent, CreateSourceState> {
     on<CreateSourceHeadquartersChanged>(_onHeadquartersChanged);
     on<CreateSourceStatusChanged>(_onStatusChanged);
     on<CreateSourceSubmitted>(_onSubmitted);
+    on<CreateSourceDataUpdated>(_onDataUpdated);
   }
 
   final DataRepository<Source> _sourcesRepository;
@@ -130,4 +131,11 @@ class CreateSourceBloc extends Bloc<CreateSourceEvent, CreateSourceState> {
       );
     }
   }
+
+  void _onDataUpdated(
+    CreateSourceDataUpdated event,
+    Emitter<CreateSourceState> emit,
+  ) {
+    emit(state.copyWith(countries: event.countries, languages: event.languages));
+  }
 }

lib/content_management/bloc/create_source/create_source_event.dart

@@ -70,3 +70,17 @@ final class CreateSourceStatusChanged extends CreateSourceEvent {
 final class CreateSourceSubmitted extends CreateSourceEvent {
   const CreateSourceSubmitted();
 }
+
+/// Event to update the BLoC with the latest shared data.
+final class CreateSourceDataUpdated extends CreateSourceEvent {
+  const CreateSourceDataUpdated({
+    required this.countries,
+    required this.languages,
+  });
+
+  final List<Country> countries;
+  final List<Language> languages;
+
+  @override
+  List<Object?> get props => [countries, languages];
+}