Add WithOperationNameSetter to allow control of the operation name sent to metrics

[lwc]

This allows folks to customise the operation name attribute sent on metrics.

The signature is the same as the SpanNameFormatter, so the same function could be used for both, which is probably generally desirable.

Potentially so desirable, that we could avoid the second config option and always do this, but this has better BC.

[codecov]

Codecov Report

❌ Patch coverage is 64.70588% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.7%. Comparing base (92a17e7) to head (f2feff8).

Files with missing lines	Patch %	Lines
utils.go	53.8%	3 Missing and 3 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main    #595     +/-   ##
=======================================
- Coverage   85.3%   80.7%   -4.7%     
=======================================
  Files         16      16             
  Lines        752     788     +36     
=======================================
- Hits         642     636      -6     
- Misses        74     102     +28     
- Partials      36      50     +14     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.