nightly-2024-09-10: fix: suggest trait attributes in LSP (#5972)

# Description

## Problem

I noticed LSP didn't suggest trait attributes... because these weren't
visited. I also noticed when an attribute related to a function was
suggested, but the function only had one argument, the parentheses were
included in the suggestion but they aren't needed.

## Summary

Fixes the above problems.


![lsp-trait-attribute](https://github.com/user-attachments/assets/16cdd8ab-1d03-40d1-a1b1-19b26d88e322)

## Additional Context



## Documentation

Check one:
- [x] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[For Experimental Features]** Documentation to be submitted in a
separate PR.

# PR Checklist

- [x] I have tested the changes locally.
- [x] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.