Coins analysis for const generics

[xunilrj]

Description

This PR continue #7391.

First, it removes some easy todo!() around ParsedDeclId. It seems only fn or struct are using those. But I decided to implement them anyway to keep the code uniform. We may be able to simplify this, I think.

Second, it implements coin analysis for const generics. Unfortunately, the analysis runs on the fn declaration and not on the materialised version. So even calling a function with 0 generates the error.

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 #7473 will not alter performance

_{Comparing xunilrj/removing-const-generics-todos-2 (82959e3) with master (90c8ed2)}

Summary

✅ 25 untouched