fix(translations): Complete and correct French fr-FR translations

[Tseacen]

• Added missing French translations for various labels and messages.
• Corrected incorrect translations to ensure accuracy and consistency.
• Improved clarity and readability of the French language content.

[vercel[bot]]

@Tseacen is attempting to deploy a commit to the umami-software Team on Vercel.

A member of the Team first needs to authorize it.

[Maxime-J]

Hi,

You should only update https://github.com/umami-software/umami/blob/master/src/lang/fr-FR.json The file currently modified is 'built' from this one, and can more likely introduce issues.

For instance, the "type": 1 strings you changed would have break things, those are not intended to be translated, which is easier to understand with the src lang file.

Concerning the translations themselves:

message.visitors-dropped-off is used in app like 20 Visitors dropped off so it can't be 20 Les visiteurs ont abandonné

the accent used for événement is questionnable, I had opted for the Académie Française recommendation with the new admitted spelling.

I'm not very fan of Ce mois-ci especially as it's not done with week and year.

--

But anyway, there are no attributed language reviewers, so all updates are welcomed 👍