Add French localization

[mtardy]

Saw your proposal to write localization in the release notes and since I love using Secretive I did the one for French 🇫🇷!

I just had hesitation on how to translate the agent_(not_)running_notice_title because it's a bit inconsistent between using "Agent" (and click to see the details) and "Secret Agent":

• agent_not_running_notice_title: Secret Agent Is Not Running
• agent_running_notice_title: Agent is Running

So I translated that to the French common name with a determinant: "L'agent"

The rest should be fine!

[maxgoedjen]

@mtardy this is fantastic, thank you so much for doing this! I'm gonna merge this one now, but I just noticed a handful of strings I missed (mainly around the little password/Touch ID prompts for secured keys) on my first pass. If you don't mind, can I tag you on the followup PR I'll have adding those?

agent_not_running_notice_title: Secret Agent Is Not Running
agent_running_notice_title: Agent is Running

Yeah, there's no real consistency on my part there. I should update that in English as well ;)

[maxgoedjen]

Those changes are here: #507
I've also consolidated both localizations (including your previous translations) into one single localization file, so it should be a little simpler to deal with in the future. Thank you again!

[mtardy]

@mtardy this is fantastic, thank you so much for doing this!

I'm really glad you liked it 😌! I will retake a look then since you merged #507.