fix: when macro parse error happens, discard warnings; also preserve unquoted token locations

[asterite]

Description

Problem

No issue, just something confusing mentioned over Slack that could be improved.

Summary

Two things here:

1. When a macro parse error happened we'd show the just first error. The issue was that in the list of "errors" warnings could exist too. So here we discard warnings and truly show the first error. (Maybe ideally we'd show all errors and warnings here but I'm not sure how we'd show that as a result of a macro expansion, so I did the minimum thing to improve the situation without introducing a large change).
2. The location of the $expr token ended up being the location of the quote expression that held it, making errors point to that entire quote (as can be seen in the second commit). This was likely done before everything started holding a Location instead of a Span. The second improvement here is to preserve those token locations. The third commit shows how the error improves.

In the actual code with the confusing error message, this is what we initially saw in VSCode:

This is the warning caused by not being able to parse the macro.

Once that was fixed (first commit), we got this error:

It actually continues above and below that: it's the entire quote { ... } that has the error.

With the third commit we get this error:

with the error being "Expected value, found built-in type (resolved type)". So now it's much clearer where's the error.

Additional Context

Documentation

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark 'Test Suite Duration'.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 1.20.

Benchmark suite	Current: e701428	Previous: 5071093	Ratio
test_report_AztecProtocol_aztec-packages_noir-projects_noir-protocol-circuits_crates_blob	219 s	149 s	1.47
test_report_noir-lang_noir_bigcurve_	293 s	239 s	1.23

This comment was automatically generated by workflow using github-action-benchmark.

CC: @TomAFrench

[TomAFrench]

Looks like the snapshot is incorrect.