fix(content_management): remove implicit call and improve repository access

- Remove implicit call to CreateSourceBloc
- Replace direct repository access with context.read<DataRepository>()
- Apply the same change to countriesRepository and languagesRepository

Author: fulleni

lib/content_management/view/create_source_page.dart

@@ -20,7 +20,7 @@ class CreateSourcePage extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return BlocProvider(
-      create: (context) => CreateSourceBloc(sourcesRepository: sourcesRepository, countriesRepository: countriesRepository, languagesRepository: languagesRepository)(
+      create: (context) => CreateSourceBloc(
         sourcesRepository: context.read<DataRepository<Source>>(),
         countriesRepository: context.read<DataRepository<Country>>(),
         languagesRepository: context.read<DataRepository<Language>>(),