Use compiler source map directly in forc-debug

[JoshuaBatty]

Description

Replace the custom HashMap-based source map implementation in forc-debug with the compiler's source map format directly. This simplifies our source mapping logic and maintains better consistency with the compiler's source location tracking, while preserving all existing functionality.

Key changes:

• Remove custom source map types and use compiler's SourceMap
• Simplify breakpoint verification using compiler spans
• Add test to verify source map instruction-to-line mappings

closes #6733

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.

[sdankel]

Looks good to me 🚀 Just left one comment on what Kaya pointed out. It could be done in a future PR.