l10n: port mkdir to translation + add french

[sylvestre]

No description provided.

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/du/one-file-system. tests/du/one-file-system is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/mkdir/p-1. tests/mkdir/p-1 is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/mkdir/p-2. tests/mkdir/p-2 is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/mkdir/p-3. tests/mkdir/p-3 is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/rmdir/ignore. tests/rmdir/ignore is passing on 'main'. Maybe you have to rebase?

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/timeout/timeout (fails in this run but passes in the 'main' branch)