Display all supported languages in drawer

Steps to reproduce:
1. Create a page "A"
2. Set the wiki on multilingual
3. Set two Supported Languages (or more), for example: English and German
4. Go to page "A" and Look in the Administration drawer > Languages (English language will be displayed)
5. Create a page "B" with default language German and Look in the Administration drawer > Languages (German language will be displayed)
6. Translate the page "B" in English and Look in the Administration drawer > Languages (English and German languages will be displayed)

Expected results:
1. You can change the language from Administration drawer to an other Supported Language.

Actual results:
1. Only the language of the current document and it's translations is displayed, as I was mentioning at point 4 and 5.

In a multilingual wiki when you are on page with only one language set and you want to swap to an other language, the supported language are not displayed in the drawer. Only the current document languages is displayed. So you have to go and search an other page that is translated and change the language from there.