[FR] Update `Client\interface\Multiplayer`

[Biokax]

This is a fully retranslated version of Multiplayer so its better to review this as a new file instead of an update.

This is also the final PR before getting 0 on clayton.cc for french language (pog moment)

• [x] The changes are tested against the contribution checklist
• [ ] (translations only) The changes are reviewed on GitHub by a fluent speaker