fix(account): update followed countries title text

- Replace 'l10n.accountFollowedCountriesTile' with 'l10n.headlinesFeedFilterCountryLabel'
- This change ensures the correct and consistent label is displayed for the followed countries section

Author: fulleni

lib/account/view/manage_followed_items/manage_followed_items_page.dart

@@ -65,7 +65,7 @@ class ManageFollowedItemsPage extends StatelessWidget {
               color: colorScheme.primary,
             ),
             title: Text(
-              l10n.accountFollowedCountriesTile,
+              l10n.headlinesFeedFilterCountryLabel,
               style: textTheme.titleMedium,
             ),
             trailing: const Icon(Icons.chevron_right),