refactor(entity-details): remove adService from FeedDecoratorService

- Remove unused AdService dependency from FeedDecoratorService
- Simplify FeedDecoratorService constructor by removing adService parameter
- Update EntityDetailsPage to not provide adService to FeedDecoratorService

Author: fulleni

lib/entity_details/view/entity_details_page.dart

@@ -52,11 +52,9 @@ class EntityDetailsPage extends StatelessWidget {
       create: (context) {
         final topicsRepository = context.read<DataRepository<Topic>>();
         final sourcesRepository = context.read<DataRepository<Source>>();
-        final adService = context.read<AdService>();
         final feedDecoratorService = FeedDecoratorService(
           topicsRepository: topicsRepository,
           sourcesRepository: sourcesRepository,
-          adService: adService,
         );
         final entityDetailsBloc =
             EntityDetailsBloc(