[Turbopack] Include CSS URL attributes, including Layer, Media and Supports

[robert-j-webb]

Note that this is my first contribution in Rust, so let me know if I missed anything idiomatic or if there is a particularly better way to do something.

Also, I did not use AI to create this at all, although I did chat a bit to try to wrap my head around types.

• Related issues linked using Fixes CSS layers are incorrectly stripped from output #88533
• Tests added.
• Errors have a helpful link attached, see https://github.com/vercel/next.js/blob/canary/contributing.md

Summary of changes: Adds support for all of the attributes of @import for Turbopack, by modifying the turbopack-css package, including Layer, Media and Supports. W3 Reference

[codspeed-hq]

CodSpeed Performance Report

Merging this PR will not alter performance

_{Comparing robert-j-webb:canary (d392602) with canary (af18c32)}

Summary

✅ 17 untouched benchmarks
⏩ 3 skipped benchmarks¹

Footnotes

1. 3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩