Problem/Motivation
When editing a node translation, the menu link information shown is from the original language, not the translation itself.
Steps to reproduce:
* Add a language (e.g. Spanish)
* Enable content translation for the page content.
* Enable content translation for the custom menu links.
* Create a node in English providing a menu link in menu settings
* Translate the node to Spanish.
* Translate the menu link to Spanish.
* Go to the edit translation form in Spanish.
Expected output: the menu item in the menu settings tab is in Spanish
Current output: the menu item in the menu settings tab is in English
Proposed resolution
Load the proper translation if any.
Remaining tasks
Provide a first patch.
User interface changes
The menu item in the edit form will be in the same language than the content being edited.
API changes
None, hopefully.
Data model changes
None.