Implement the GUI for cross-language search.
- The user can search ElasticSearch in any language; we can reuse the facets to filter what language is searched.
- A language selector to "convert" all messages (keys) to their corresponding messages in another languages.
- A switch to show all, untranslated, translated, outdated messages. Example: Nikerabbit> Nemo_bis: search for "please log in" finds one message in English. If your target language is, say hippopotania, it is not translated in that language but we can display it as untranslated message and allow user to translate it there