feat(headlines-feed): add followed countries to CountriesFilterState

- Add followedCountriesStatus and followedCountries properties to CountriesFilterState
- Update copyWith method to include new parameters for followed countries
- Modify props list to include new state properties

Author: fulleni

lib/headlines-feed/bloc/countries_filter_state.dart

@@ -34,6 +34,8 @@ final class CountriesFilterState extends Equatable {
     this.hasMore = true,
     this.cursor,
     this.error,
+    this.followedCountriesStatus = CountriesFilterStatus.initial,
+    this.followedCountries = const [],
   });
 
   /// The current status of fetching countries.
@@ -52,15 +54,24 @@ final class CountriesFilterState extends Equatable {
   /// An optional error object if the status is [CountriesFilterStatus.failure].
   final HttpException? error;
 
+  /// The current status of fetching followed countries.
+  final CountriesFilterStatus followedCountriesStatus;
+
+  /// The list of [Country] objects representing the user's followed countries.
+  final List<Country> followedCountries;
+
   /// Creates a copy of this state with the given fields replaced.
   CountriesFilterState copyWith({
     CountriesFilterStatus? status,
     List<Country>? countries,
     bool? hasMore,
     String? cursor,
     HttpException? error,
+    CountriesFilterStatus? followedCountriesStatus,
+    List<Country>? followedCountries,
     bool clearError = false,
     bool clearCursor = false,
+    bool clearFollowedCountriesError = false,
   }) {
     return CountriesFilterState(
       status: status ?? this.status,
@@ -70,9 +81,20 @@ final class CountriesFilterState extends Equatable {
       cursor: clearCursor ? null : (cursor ?? this.cursor),
       // Clear error if requested, otherwise keep existing or use new one
       error: clearError ? null : error ?? this.error,
+      followedCountriesStatus:
+          followedCountriesStatus ?? this.followedCountriesStatus,
+      followedCountries: followedCountries ?? this.followedCountries,
     );
   }
 
   @override
-  List<Object?> get props => [status, countries, hasMore, cursor, error];
+  List<Object?> get props => [
+    status,
+    countries,
+    hasMore,
+    cursor,
+    error,
+    followedCountriesStatus,
+    followedCountries,
+  ];
 }