Add localized search functionality for contacts (#244)

- Introduced new localization keys for searching contacts, users, favorites, repeaters, and room servers in multiple languages.
- Updated localization files for Italian, Bulgarian, German, English, Spanish, French, Dutch, Polish, Portuguese, Russian, Slovak, Slovenian, Swedish, Ukrainian, and Chinese.
- Enhanced the contacts screen to dynamically display search hints based on the selected contact type filter.
- Modified the map screen to utilize the new search functionality for contacts without a number.

lib/screens/contacts_screen.dart

@@ -402,6 +402,41 @@ class _ContactsScreenState extends State<ContactsScreen>
         ? const <ContactGroup>[]
         : _filterAndSortGroups(_groups, contacts);
 
+    String hintText = "";
+
+    switch (_typeFilter) {
+      case ContactTypeFilter.all:
+        hintText = context.l10n.contacts_searchContacts(
+          filteredAndSorted.length,
+          _showUnreadOnly ? " ${context.l10n.contacts_unread}" : "",
+        );
+        break;
+      case ContactTypeFilter.users:
+        hintText = context.l10n.contacts_searchUsers(
+          filteredAndSorted.length,
+          _showUnreadOnly ? " ${context.l10n.contacts_unread}" : "",
+        );
+        break;
+      case ContactTypeFilter.repeaters:
+        hintText = context.l10n.contacts_searchRepeaters(
+          filteredAndSorted.length,
+          _showUnreadOnly ? " ${context.l10n.contacts_unread}" : "",
+        );
+        break;
+      case ContactTypeFilter.rooms:
+        hintText = context.l10n.contacts_searchRoomServers(
+          filteredAndSorted.length,
+          _showUnreadOnly ? " ${context.l10n.contacts_unread}" : "",
+        );
+        break;
+      case ContactTypeFilter.favorites:
+        hintText = context.l10n.contacts_searchFavorites(
+          filteredAndSorted.length,
+          _showUnreadOnly ? " ${context.l10n.contacts_unread}" : "",
+        );
+        break;
+    }
+
     return Column(
       children: [
         Padding(
@@ -409,7 +444,7 @@ class _ContactsScreenState extends State<ContactsScreen>
           child: TextField(
             controller: _searchController,
             decoration: InputDecoration(
-              hintText: context.l10n.contacts_searchContacts,
+              hintText: hintText,
               prefixIcon: const Icon(Icons.search),
               suffixIcon: Row(
                 mainAxisSize: MainAxisSize.min,

lib/screens/map_screen.dart

@@ -1301,7 +1301,8 @@ class _MapScreenState extends State<MapScreen> {
                         padding: const EdgeInsets.fromLTRB(16, 4, 16, 8),
                         child: TextField(
                           decoration: InputDecoration(
-                            hintText: context.l10n.contacts_searchContacts,
+                            hintText:
+                                context.l10n.contacts_searchContactsNoNumber,
                             prefixIcon: const Icon(Icons.search),
                             border: OutlineInputBorder(
                               borderRadius: BorderRadius.circular(12),