SDL/WGPU support

I noticed I can't get the default frontend to run on my older laptops and my arm-based linux laptop (using the open-sourced panfrost driver). I get an error with:

```error: GLSL 3.30 is not supported. Supported versions are: 1.10, 1.20, and 1.00 ES```

I think a proper SDL renderer would solve this. I feel like this would be a great default/fallback renderer, since SDL is supported pretty much everywhere (and runs via an abstracted OpenGL/DirectX backend by default). With this we could probably even get this running on most all android devices.

Is this something that would be of interest?