improved language picker (#6890)

* improved language picker

* fix import path

* update tests

demo-shell/src/app.config.json

@@ -33,77 +33,6 @@
     "name": "Alfresco ADF Application",
     "copyright": "© 2016 - 2018 Alfresco Software, Inc. All Rights Reserved."
   },
-  "languages": [
-    {
-      "key": "en",
-      "label": "English"
-    },
-    {
-      "key": "fr",
-      "label": "Français"
-    },
-    {
-      "key": "de",
-      "label": "Deutsch"
-    },
-    {
-      "key": "it",
-      "label": "Italiano"
-    },
-    {
-      "key": "es",
-      "label": "Español"
-    },
-    {
-      "key": "ja",
-      "label": "日本語"
-    },
-    {
-      "key": "nl",
-      "label": "Nederlands"
-    },
-    {
-      "key": "pt-BR",
-      "label": "Português (Brasil)"
-    },
-    {
-      "key": "nb",
-      "label": "Bokmål"
-    },
-    {
-      "key": "ru",
-      "label": "Русский"
-    },
-    {
-      "key": "zh-CN",
-      "label": "中文简体"
-    },
-    {
-      "key": "ar",
-      "label": "عربى",
-      "direction": "rtl"
-    },
-    {
-      "key": "cs",
-      "label": "Čeština"
-    },
-    {
-      "key": "pl",
-      "label": "Polski"
-    },
-    {
-      "key": "fi",
-      "label": "Suomi"
-    },
-    {
-      "key": "da",
-      "label": "Dansk"
-    },
-    {
-      "key": "sv",
-      "label": "Svenska"
-    }
-  ],
   "search": {
     "filterWithContains": true,
     "app:fields": [