Add expose-ids feature

[TheOnlyMrCat]

Checklist

• Run cargo clippy.
• Run RUSTFLAGS=--cfg=web_sys_unstable_apis cargo clippy --target wasm32-unknown-unknown if applicable.
• Add change to CHANGELOG.md. See simple instructions inside file.

Connections
Discussed in matrix

Description
Adds the expose-ids feature, which allows API users to compare and store the identity of GPU objects through an opaque Id type. On native, Id wraps an unzipped wgc::TypedId; on web, Id wraps a manually-generated unique u64.

Most types with an id field now expose a feature-gated global_id method.

Testing
Not functionally tested yet, only typechecked

Unresolved Questions

• Should Ids be type-tagged, and if so, should there still be an untyped option?
• Should global atomics be used to guarantee uniqueness between multiple Contexts on native?

[i509VCB]

Are these changes related to #3051?

[cwfitzgerald]

@i509VCB this particular use case is for unique identification of various resources for use in a cache, they need to be globally unique, not just unique-at-any-one-time.

[codecov-commenter]

Codecov Report

Merging #3104 (1d30c08) into master (ce08179) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #3104      +/-   ##
==========================================
- Coverage   64.75%   64.74%   -0.02%     
==========================================
  Files          81       81              
  Lines       38711    38747      +36     
==========================================
+ Hits        25066    25085      +19     
- Misses      13645    13662      +17     

Impacted Files	Coverage Δ
wgpu/src/backend/direct.rs	55.25% <0.00%> (-0.48%)	⬇️
wgpu/src/lib.rs	52.81% <0.00%> (-0.06%)	⬇️
wgpu-core/src/track/texture.rs	60.18% <0.00%> (-20.66%)	⬇️
wgpu-core/src/track/buffer.rs	85.38% <0.00%> (-11.52%)	⬇️
wgpu-core/src/resource.rs	25.13% <0.00%> (-2.47%)	⬇️
wgpu-hal/src/dx12/descriptor.rs	87.56% <0.00%> (-0.50%)	⬇️
wgpu-hal/src/vulkan/adapter.rs	77.68% <0.00%> (-0.19%)	⬇️
wgpu-hal/src/gles/queue.rs	61.65% <0.00%> (-0.17%)	⬇️
wgpu-hal/src/dx12/adapter.rs	80.65% <0.00%> (-0.05%)	⬇️
... and 22 more

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[cwfitzgerald]

Looks great outside of a small comment

[cwfitzgerald]

Sorry for the long delay in reviewing

[cwfitzgerald]

Thanks!