Use pointers instead of IDs for tracing

[andyleiserson]

This resolves the duplicate storage of Id and Arc versions of commands (when tracing) that was introduced by encode-on-finish. It now stores the Arc version only, and uses the pointers from the Arcs as object IDs when tracing. It also overhauls the trace player to play back traces in this format.

This fixes tracing of compute and render passes when encoded using the standard APIs. Tracing of render bundles is still broken.

Testing
Updates the existing player tests to new trace format. Did some manual testing including in Firefox. #8429 adds directed tests for tracing.

Squash or Rebase? Rebase, after squashing fixups.

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.

[andyleiserson]

This does have all my latest local changes, but there's still a little work to do to fix the CI failures, and I want to revisit the way that polling and user_closures are handled.

[teoxoy]

I wanted to mention that the main difference I noticed between this approach and the previous is that we now effectively only record commands after successful validation. I find that this somewhat limits the usefulness of recording and replaying traces since they won't record invalid commands.

I've mostly used the record/replay functionality to debug overly restrictive or wrong validation in Firefox which will no longer be possible with this PR.

We should probably talk about this at the maintainers meeting.

[teoxoy]

We talked a bit about this at the maintainers meeting. Would it be possible to trace before validation runs (so that invalid commands get included in the trace)?

[teoxoy]

I just realized Fallible::Invalid also has type Arc<String> - we could use that address to be able to record before validation.

[andyleiserson]

Since this PR is already quite large, I opened #8429 for the error tracing support.