cherry-pick: add-ar-i18n

Merge in DNS/adguard-home from add-ar-i18n to master

Squashed commit of the following:

commit 6ef7c70bceb6f6ebabd81011154022a75fc91bd3
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Wed Aug 10 20:55:39 2022 +0300

    client: add ar locale

.twosky.json

@@ -2,8 +2,11 @@
   {
     "project_id": "home",
     "base_locale": "en",
-    "localizable_files": ["client/src/__locales/en.json"],
+    "localizable_files": [
+      "client/src/__locales/en.json"
+    ],
     "languages": {
+      "ar": "العربية",
       "be": "Беларуская",
       "bg": "Български",
       "cs": "Český",