[deno] Fix dropping of command encoders/buffers, and an enum typo

[andyleiserson]

Fixes #7797, a double-free error in deno. Command encoders, since they are the same wgpu object as the command buffer they become, should not be dropped after a buffer has been created from that encoder. Separately, I think command buffers should be explicitly dropped, even after they have been submitted.

Also fixes a typo in the GPUTextureFormat conversion.

This resolves a crash in the copyTextureToTexture tests, but they are still failing due to #7391, so they cannot be added to the regression until that is fixed.

Testing
Enables some CTS tests related to Queue.submit. As noted in a comment, the error reported if CommandEncoder.finish is called twice is not right, and I would not expect a CTS test for that to pass, but I also can't find one, so I made a note in gpuweb/cts#4401 to add it.

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.
• Run cargo xtask cts.
• If this contains user-facing changes, add a CHANGELOG.md entry.