TF-2237 Add sending text

(cherry picked from commit ff1d0d73bc2eea6619328ee07609f3a9c2ffc055)

lib/l10n/intl_messages.arb

@@ -3319,5 +3319,11 @@
       "folderName": {},
       "reason": {}
     }
+  },
+  "sending": "Sending",
+  "@sending": {
+    "type": "text",
+    "placeholders_order": [],
+    "placeholders": {}
   }
 }

lib/main/localizations/app_localizations.dart

@@ -3421,4 +3421,11 @@ class AppLocalizations {
       args: [folderName, reason]
     );
   }
+
+  String get sending {
+    return Intl.message(
+      'Sending',
+      name: 'sending',
+    );
+  }
 }