[try for v1] Add binding arrays to API

[kainino0x]

This doesn't strictly have to be in V1 but it would be nice if it can be.

Upstream proposal: https://github.com/gpuweb/gpuweb/blob/main/proposals/sized-binding-arrays.md

[kainino0x]

@Kangz what's your opinion on how stable this proposal is? Would there be any risk of future changes if we added it to the core GPUBindGroupLayoutEntry struct now?

[Kangz]

The member should be 99%+ certain to land as is. (I have it as an extension struct in Dawn right now but changing it would be easy). I can schedule a small discussion about it in the WebGPU WG for confirmation.

[kainino0x]

Apr 24 meeting:

• KN: Working group didn't think it was likely this would change.
• CF: People sometimes get confused with 2d-array texture counts. (It's just called "count" in wgpu.)
• KN: Let's pick a clear name.
• Sounds good, add it