[core] Do not use IDs as default type in PipelineLayoutDescriptor

[sagudev]

Connections
Towards #5121

Description
We want to remove IDs from wgc, so we should not use them as default types.
Testing
Just refactor.

Squash or Rebase?
Squash

Checklist

• I self-reviewed and fully understand this PR.
• WebGPU implementations built with wgpu may be affected behaviorally.
• Validation and feature gates are in place to confine behavioral changes.
• Tests demonstrate the validation and altered logic works.
• CHANGELOG.md entries for the user-facing effects of this change are present.
• The PR is minimal, and doesn't make sense to land as multiple PRs.
• Commits are logically scoped and individually reviewable.
• The PR description has enough context to understand the motivation and solution implemented.

[sagudev]

There is no cbindgen:ignore on PipelineLayoutDescriptor? Will this be problem in FF?