Add localization for chat and repeater features in multiple languages

- Added translations for "Send message", "Guest information", and "Guest tools" in Bulgarian, German, Spanish, French, Hungarian, Italian, Japanese, Korean, Dutch, Polish, Portuguese, Russian, Slovak, Slovenian, Swedish, Ukrainian, and Chinese.
- Updated the "Clock synchronization after login" feature subtitle in all affected languages.
- Removed untranslated keys from the untranslated.json file as they have now been localized.

lib/l10n/app_localizations_bg.dart

@@ -1240,7 +1240,7 @@ class AppLocalizationsBg extends AppLocalizations {
   String get chat_noMessages => 'Няма съобщения.';
 
   @override
-  String get chat_sendMessage => 'Send message';
+  String get chat_sendMessage => 'Изпратете съобщение';
 
   @override
   String chat_sendMessageTo(String contactName) {
@@ -2020,16 +2020,16 @@ class AppLocalizationsBg extends AppLocalizations {
   String get room_management => 'Управление на сървъра за стая';
 
   @override
-  String get repeater_guest => 'Repeater Information';
+  String get repeater_guest => 'Информация за ретранслаторите';
 
   @override
-  String get room_guest => 'Room Server Information';
+  String get room_guest => 'Информация за сървъра на стаята';
 
   @override
   String get repeater_managementTools => 'Инструменти за управление';
 
   @override
-  String get repeater_guestTools => 'Guest Tools';
+  String get repeater_guestTools => 'Инструменти за гости';
 
   @override
   String get repeater_status => 'Статус';