fix: Capture more declarations for sway autocomplete

[sdankel]

Description

I noticed that autocomplete wasn't working for some function declarations. It was because sometimes function declarations in the token map are stored as TyDecl::FunctionDecl(decl) and sometimes as TypedAstToken::TypedFunctionDeclaration(TyFunctionDecl {..})

This PR expands the matching for declarations to make autocomplete work in more cases.

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 #6598 will degrade performances by 17.08%

_{Comparing sophie/expand-autocomplete (50b8edd) with master (c5f363b)}

Summary

❌ 1 regressions
✅ 21 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	master	sophie/expand-autocomplete	Change
❌	document_symbol	4.4 ms	5.3 ms	-17.08%