Get WebGPU ready

[Wumpf]

Now that Chrome with default-enabled WebGPU support is around the corner we need to explore flipping the switch to WebGPU on the web.

Expecting right now that this requires using a patched wgpu version (due to the way how WebGPU and implementations move right now), therefore should regard this fore and foremost as prototype!

For the prototype we want to know how performance & file size compare and be able to talk about this on Twitter/Discord/etc.
Also, need to feedback any fixed/workarounds that might be required to wgpu and/or Chrome.

Ideally we can also land a version that supports both WebGPU and WebGL but we won't be able to do so ofc if this requires a non-published wgpu version.

[emilk]

I suggest we time-box this to two days, to see how far we get, what the obstacles are, and then open new issues base on that.