fix: allow importing ESM interface and reporters

[Lightning00Blade]

PR Checklist

• Addresses an existing open issue: fixes 🐛 Bug: Can't ESM (default) import custom interfaces and reporters #5562
• That issue was marked as status: accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

A very simple (and rough) PR to show case where the issue is. It only unwraps modules default if present.

[mark-wiemer]

Thanks @Lightning00Blade , can you add a unit test that would've failed before but passes with your code changes?

[Lightning00Blade]

@mark-wiemer I added the requested tests verified they don't pass on main.

I also strongly want to emphasize that PR #5344 should be merged as well,
even without test as where this bug was happening was easier once I had similar patch applied to the one proposed in the PR.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.53%. Comparing base (9cc3ada) to head (e6c338e).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5563   +/-   ##
=======================================
  Coverage   93.52%   93.53%           
=======================================
  Files          57       57           
  Lines        4465     4469    +4     
  Branches      918      920    +2     
=======================================
+ Hits         4176     4180    +4     
  Misses        289      289           

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[JoshuaKGoldberg]

Super. I verified locally that this passes with the repro case in #5562 (comment). Just one more test and I think we'll be good to go! 🚀