chore(mobile): translate toast messages (#17964)

i18n/en.json

@@ -1226,6 +1226,8 @@
   "month": "Month",
   "monthly_title_text_date_format": "MMMM y",
   "more": "More",
+  "moved_to_archive": "Moved {count, plural, one {# asset} other {# assets}} to archive",
+  "moved_to_library": "Moved {count, plural, one {# asset} other {# assets}} to library",
   "moved_to_trash": "Moved to trash",
   "multiselect_grid_edit_date_time_err_read_only": "Cannot edit date of read only asset(s), skipping",
   "multiselect_grid_edit_gps_err_read_only": "Cannot edit location of read only asset(s), skipping",

mobile/lib/utils/selection_handlers.dart

@@ -8,6 +8,7 @@ import 'package:immich_mobile/extensions/build_context_extensions.dart';
 import 'package:immich_mobile/providers/asset.provider.dart';
 import 'package:immich_mobile/services/asset.service.dart';
 import 'package:immich_mobile/services/share.service.dart';
+import 'package:immich_mobile/utils/translation.dart';
 import 'package:immich_mobile/widgets/common/date_time_picker.dart';
 import 'package:immich_mobile/widgets/common/immich_toast.dart';
 import 'package:immich_mobile/widgets/common/location_picker.dart';
@@ -57,12 +58,13 @@ Future<void> handleArchiveAssets(
         .read(assetProvider.notifier)
         .toggleArchive(selection, shouldArchive);
 
-    final assetOrAssets = selection.length > 1 ? 'assets' : 'asset';
-    final archiveOrLibrary = shouldArchive ? 'archive' : 'library';
+    final message = shouldArchive
+        ? t('moved_to_archive', {'count': selection.length})
+        : t('moved_to_library', {'count': selection.length});
     if (context.mounted) {
       ImmichToast.show(
         context: context,
-        msg: 'Moved ${selection.length} $assetOrAssets to $archiveOrLibrary',
+        msg: message,
         gravity: toastGravity,
       );
     }

mobile/lib/utils/translation.dart

@@ -0,0 +1,14 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:intl/message_format.dart';
+
+String t(String key, [Map<String, Object>? args]) {
+  try {
+    String message = key.tr();
+    if (args != null) {
+      return MessageFormat(message).format(args);
+    }
+    return message;
+  } catch (e) {
+    return key;
+  }
+}