French L10n

[jpcima]

This is the 🇫🇷 translation. All strings are done, but some verification will be nice.
Expecting for @trebmuh to validate and give us the green light.

I reworked a few elements of sources.

• "notr" where appropriate
• I have named or renamed current toolbars, which appear in the right click context menu: Main toolbar, Secondary toolbar.

Also: please consider PR #61 to help have a working build process for most setups.

[trebmuh]

Pretty much all good for me. @jpcima I made a PR on your fork with a few improvements/fixes, after what, everything looks fine to me and is ready to be merged here from my POV.

[jpcima]

I believe it's fine to merge at this current state, you can go ahead.

It's still been on discussion whether individual contents of the PR above are actually appropriate, and personnally I think they aren't; we can make a followup PR happen if needed.
Current state is fine, it's not necessary to put it on wait.

[trebmuh]

OK for merging it as is.

[rerrahkr]

Thanks for your contributions!