Splat Sort Worker Algorithm Updates

[SimonDaKappa]

The current splat renderer has a background thread that sorts all splats based on depth. This is a single cpu sort, and runs at about 5-10fps compared to the >60fps on the main render thread. For most cases, this is fine, as the user isnt moving around a scene like they are in cod, but it would still be nice to get a better algorithm. Inria uses a GPU Bitonic sort for their depth buffers, and we could try to use WebGPU to do the same, but that seems to be an issue a lot of adjacent renderers online have ran into. We could also investigate into float-based radix sorts, as most of the depths arent super large.

See:
https://www.codercorner.com/RadixSortRevisited.htm
http://stereopsis.com/radix.html
https://webgpu.github.io/webgpu-samples/?sample=bitonicSort
https://github.com/hjlld/webgpu-bitonic-sort
https://gwebgpu.antv.vision/en/examples/gpgpu/basic/bitonicSort

This is pretty low priority, but it'd be cool to improve nonetheless