Parse raw identifiers (r#<identifier>) in expressions

[ironcev]

Description

This PR fixes several issues related to raw identifiers (r#<identifier>). The focus was to fix only the major issue that was preventing the planned migration step for panic expression to be implemented. The planned step "Rename existing "panic" identifiers" will replace all eventual occurrences of panic with r#panic. For that, it was crucial to get raw identifiers being properly parsed in expressions.

The PR:

• fixes Parser does not treat properly raw identifiers that represent keywords #7066.
• fixes Auto implementation panics when raw identifiers are used for item names #7134.
• fixes Auto implementation panics when raw identifiers are used for fallback function name #7135.

Some remaining issues related to raw identifiers are documented in #7136.

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

[codspeed-hq]

CodSpeed Performance Report

Merging #7137 will not alter performance

_{Comparing ironcev/keywords-as-raw-identifiers (349d310) with master (42321ef)}

Summary

✅ 22 untouched benchmarks