Add multiview limits and tests

[SupaMaggie70Incorporated]

Connections
Addresses #7196 and #8138

Description
Adds new limits and testing for multiview, add support for more backends (also in naga), add new multiview bitmask renderpass descriptor field for selecting which layers to render to in a single pass.

CURRENTLY WAITING ON #8110

Marking as open because its had progress made and I think this is about what it will look like when complete, even though its completely broken at the moment. Also because I want to get it in the pipeline sooner rather than later. Just the following remaining.

TODO:

• Currently the implementation is completely broken on ALL platforms (very impressive tbh).
  • On my Macbook, it for some reason sets all texture bytes to 255 outside of the first pass?
  • On every other platform, including MacOS CI, it zeroes the texture
• Make DX12 backend check for dxc with support for SM6.1+
• Implement on DX12 backend in general. Waiting on [hal/dx12] Mesh Shaders #8110, which covers tons of the same code and overwrites it.

Testing
There are tests

Squash or Rebase?
Squash

Checklist

• Run cargo fmt.
• Run taplo format.
• Run cargo clippy --tests. If applicable, add:
  • --target wasm32-unknown-unknown
• Run cargo xtask test to run tests.
• If this contains user-facing changes, add a CHANGELOG.md entry.

[SupaMaggie70Incorporated]

@cwfitzgerald I left a comment about this in matrix but it got hidden by newer messages. Is it a bad idea to add another multi view related field to a render pass descriptor? This might be a topic worth bringing up in a meeting, I'm not sure. I'm just hesitant to assume that's fine because if I'm wrong then I will have refactored every use of render passes in this entire repo :)

Not urgent of course

EDIT: This has been answered

[SupaMaggie70Incorporated]

I'm going to explicitly ping @crowlKats since I made changes to the deno API that I'm not sure make sense. I tried to copy from where I saw mask being used e.g. in GPUMultisampleState but I'm not sure if I should've also made in nullable, or split it into its own type, etc.