feat(admin): group navigation into media, uploads and system

packages/i18n/locales/en/common.json

@@ -50,6 +50,9 @@
     "main": "Navigation",
     "home": "Home",
     "admin": "Admin",
+    "admin_media": "Media library",
+    "admin_uploads": "Uploads",
+    "admin_system": "System",
     "users": "Users",
     "audit": "Audit log",
     "library": "Library",

packages/i18n/locales/ru/common.json

@@ -50,6 +50,9 @@
     "main": "Навигация",
     "home": "Главная",
     "admin": "Админка",
+    "admin_media": "Медиатека",
+    "admin_uploads": "Загрузки",
+    "admin_system": "Система",
     "users": "Пользователи",
     "audit": "Журнал",
     "library": "Библиотека",