refactor(shared): remove unused constants and update localization

- Remove constants file and pagination constants
- Update ContentStatusL10n extension to use AppLocalizationsX
- Remove constants export from shared.dart

Author: fulleni

lib/shared/constants/constants.dart

@@ -6,7 +6,7 @@ import 'package:ht_shared/ht_shared.dart';
 extension ContentStatusL10n on ContentStatus {
   /// Returns the localized string for the status.
   String l10n(BuildContext context) {
-    final l10n = context.l10n;
+    final l10n = AppLocalizationsX(context).l10n;
     switch (this) {
       case ContentStatus.active:
         return l10n.contentStatusActive;

lib/shared/constants/pagination_constants.dart

@@ -4,5 +4,4 @@
 /// the application to promote consistency and maintainability.
 library;
 
-export 'constants/constants.dart';
 export 'extensions/extensions.dart';