check translation string

[Crash--]

We will add a check between fr/en/whatever.json files to see if we have difference between files (#1296), but we also need to parse the all app to extract string and check if the string is in the main translation file in order to avoid to use untranslated string (context cozy/cozy-drive@025dcf0 string used but not defined)

[ptbrowne]

Closing since I put the link to a feature from banks that does that in #1296.