[DRAFT] Performance metrics

[CommanderStorm]

Launch Checklist

• Confirm your changes do not include backports from Mapbox projects (unless with compliant license) - if you are not sure about this, please ask!
• Briefly describe the changes in this PR.
• Link to related issues.
• Include before/after visuals or gifs if this PR includes visual changes.
• Write tests for all new functionality.
• Document any changes to public APIs.
• Post benchmark scores.
• Add an entry to CHANGELOG.md under the ## main section.

This PR is a draft how to rewrite the performance metric subsystem into something akin to a public metric.
This is not ready and likely needs a bit of feedback on slack on which metrics we actually want.
It is optional and should treeshake out nicely.

Purposely a draft to be able to ask on slack what is actually needed.

[codecov]

Codecov Report

❌ Patch coverage is 16.98113% with 44 lines in your changes missing coverage. Please review.
✅ Project coverage is 92.39%. Comparing base (933100a) to head (5f2792e).

Files with missing lines	Patch %	Lines
src/util/performance.ts	4.54%	42 Missing ⚠️
src/ui/map.ts	77.77%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7077      +/-   ##
==========================================
- Coverage   92.53%   92.39%   -0.14%     
==========================================
  Files         288      288              
  Lines       23928    23940      +12     
  Branches     5081     5091      +10     
==========================================
- Hits        22141    22120      -21     
- Misses       1787     1820      +33     

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[HarelM]

That might be an interesting addition to Maputnik for example, when editing a style.
Thanks for looking into this.