feat(mobile): iOS background sync notifications (#1811)

* adds notification handling logic

* notification on background updates for iOS

* fixed regression where i accidentally removed load translations from the background sync

* fixed ios translations

---------

Co-authored-by: Marty Fuhry <marty@fuhry.farm>
Co-authored-by: Alex <alex.tran1502@gmail.com>

mobile/lib/modules/backup/background_service/background.service.dart

@@ -314,10 +314,9 @@ class BackgroundService {
             return false;
           }
 
-          // Notifications aren't enabled in iOS yet, and this line
-          // below crashes the iOS background service
-          if (Platform.isAndroid) {
-            await loadTranslations();
+          final translationsOk = await loadTranslations();
+          if (!translationsOk) {
+            debugPrint("[_callHandler] could not load translations");
           }
 
           final bool ok = await _onAssetsChanged();