Remove dependence on regl

[rreusser]

I'd love for regl to be an afterthought and refactor the core of this module not to actually depend on it. I don't quite know what it means though to write a raw WebGL 1/2 module which uses advanced features but doesn't require an agonizing amount of very specialized interfacing in order to use. Vlad's WebGL 2 boilerplate is certainly very interesting as a potential approach, though until it grows to encompass all of the underlying API surface area, it sort of feels like an all-or-none buy in; you either have to go all the way down to the level of individual WebGL API calls or all the way up to the level of a library which entirely wraps it (threejs, regl). Unless a lightweight wrapper would allow you to just make the raw WebGL calls yourself, which may be the case.

[KTRosenberg]

Now that WebGPU is coming out soon, a parallel implementation in that might also be worth exploring, as it makes things a lot easier on the compute side.