0.79 - SDL3GPU renderer

Lots of progress

• fog
• skybox
• improve car rendering
• peds rendering

it's driveable-ish (handling issues), physics issues
brender hardware acceleration is used for sdl3gpu or opengl renderers (by default sdl3gpu is being used, still no toggle option implemented to choose between them)

New release

Still not playable but music, HUD timer, damage meter, control car and mapview already works

First release

Initial release, still WIP but goes in-race, physics not completed to make it playable