Update French localization

[surfdude29]

Following on from #4662, this PR adds translations for new strings and makes a tweak to an existing string.

I'd be grateful if you could take a look @Signez 🙏

[Signez]

Great work as usual — and good catch of the missing d’actu (even though it wasn’t actually a problem, as it could have been understood thanks to the context).

[surfdude29]

Correction applied, thanks yet again @Signez! :)

[pfrazee]

Thanks all!