Add compute dispatch indirect API

[stefnotch]

Fix https://forum.babylonjs.com/t/compute-shader-indirect-dispatching/49542

Underlying API is https://developer.mozilla.org/en-US/docs/Web/API/GPUComputePassEncoder/dispatchWorkgroupsIndirect

[bjsplat]

Please make sure to label your PR with "bug", "new feature" or "breaking change" label(s).
To prevent this PR from going to the changelog marked it with the "skip changelog" label.

[stefnotch]

Ok, how do I label this PR?

[bjsplat]

Please make sure to label your PR with "bug", "new feature" or "breaking change" label(s).
To prevent this PR from going to the changelog marked it with the "skip changelog" label.

[Popov72]

Good job!

[bjsplat]

Please make sure to label your PR with "bug", "new feature" or "breaking change" label(s).
To prevent this PR from going to the changelog marked it with the "skip changelog" label.

[stefnotch]

@Popov72 Thanks for the excellent feedback. I should have implemented it, which makes this PR ready.

I can, of course, wait until #14931 is merged, and then recreate this PR.

[bjsplat]

Snapshot stored with reference name:
refs/pull/14970/merge

Test environment:
https://babylonsnapshots.z22.web.core.windows.net/refs/pull/14970/merge/index.html

To test a playground add it to the URL, for example:

https://babylonsnapshots.z22.web.core.windows.net/refs/pull/14970/merge/index.html#WGZLGJ#4600

Links to test babylon tools with this snapshot:

https://playground.babylonjs.com/?snapshot=refs/pull/14970/merge
https://sandbox.babylonjs.com/?snapshot=refs/pull/14970/merge
https://gui.babylonjs.com/?snapshot=refs/pull/14970/merge
https://nme.babylonjs.com/?snapshot=refs/pull/14970/merge

To test the snapshot in the playground with a playground ID add it after the snapshot query string:

https://playground.babylonjs.com/?snapshot=refs/pull/14970/merge#BCU1XR#0

[bjsplat]

WebGL2 visualization test reporter:

https://babylonsnapshots.z22.web.core.windows.net/refs/pull/14970/merge/testResults/webgl2playwright/index.html

[bjsplat]

Visualization tests for WebGPU (Experimental)
Important - these might fail sporadically. This is an optional test.

https://babylonsnapshots.z22.web.core.windows.net/refs/pull/14970/merge/testResults/webgpuplaywright/index.html

[sebavan]

#14931 will be merged on Monday

[stefnotch]

Oh sweet, there weren't even any merge conflicts. This should be ready for merging (as soon as the pipeline is green).