[OLD] Fix TIC-80 when using a French AZERTY layout

[aliceisjustplaying]

Fixes #2520. alt+[grave]12345 is not triggered if an AZERTY layout is set (the user can still use esc + function keys). This allows AZERTY keyboards to fully (as far as I can tell) work with TIC-80.

There is also some groundwork laid for a potential fix of #1761 in the future, as well as detecting other layouts; this is more work though and definitely a separate PR. Let me know if you'd rather not have this bit and I can dumb it down to strictly detecting AZERTY.

Tested on MacOS 14, Windows 11 and Linux (EndeavourOS/Arch + Wayland + KDE Plasma 6).

Notes for Linux:

• All SDL2 apps, therefore TIC-80 as well run under Xwayland by default. Keyboard layout change detection will only work if done via setxkbmap (or something that calls that). If I change the keyboard from KDE Plasma 6 directly, the layout change itself it is not passed down/detected. There isn't anything we can do about this.
• TIC-80 doesn't work when forced to Wayland (SDL_VIDEODRIVER=wayland), only Xwayland. It appears to start and has audio but no window is shown. That's a separate bug to track down. Created TIC-80 doesn't work when forced to run under Wayland #2660.
• alt+1 will insert a 1 for some reason when already on the code tab. That's a separate bug to track down, and is not related to this PR. Created Ifalt+1 produces a key that's valid in TIC-80, it gets inserted in the code editor instead of executing the shortcut #2661.