Core french localisation

Including app and one module (as a test)

- I'm feeling a bit surprised about one thing, in modules, there's the info.json file with the "example" key, which seems to be the displayed examples on screen (at least for the shutdown modules it is) that can't be translated, and an examples.txt file that can be translated, but i can't find where theses examples are shown.


Anyway, i'll keep going with other modules.