* add missing locales for French translation
* accent "Media" in the front-end locales
* images => médias
* Change 'rapport' to 'signalement' in French locales to be more coherent
* fix typo
* remove duplicate EN locale
* translate missing locales
* update missing locale
* fix typo
* unify with "utilisateur⋅ice⋅s"
* address PR comments
* Add FR locale for the onboarding modal component
* Slightly increase the max-width and max-height of the onboarding modal
This is done so it doesn't break with locales whose strings would be
too long
* Update FR locales for onboarding upon PR comments
Damien Erambert