Add more SDL3 related functions

[coat]

Adds setMainReady setAppMetadata, and renderDebugText SDL3 functions.

[hazeycode]

Thanks! Note that per the SDL docs, SDL_SetAppMetadata and SDL_RenderDebugText can produce errors. Usually in this case we return an error set instead of a bool, see init for example. Unfortunately, it looks like there are some bindings (such as setHint) that aren't following this pattern.

[coat]

Thanks! Note that per the SDL docs, SDL_SetAppMetadata and SDL_RenderDebugText can produce errors. Usually in this case we return an error set instead of a bool, see init for example. Unfortunately, it looks like there are some bindings (such as setHint) that aren't following this pattern.

Ahh thanks, should've read the docs closer 😅 This should be fixed now. Happy to fix up those bindings in another PR.

[hazeycode]

Thanks!