No way to switch back to original language after looking to a translation

Step to reproduce:

1) Put the wiki in multilingual mode
2) Set available language to en,fr,de
3) Create any document in all the languages, could use the existing Sandbox home but this lead to mis-qualification of the issue (see XWIKI-11244)
4) Switch to any translation (not the original), the language menu only propose translated languages, never the original document language