refactor(instrumentation-mysql2): improve performance of getSpanName using substring

[geotry]

Which problem is this PR solving?

We noticed that getSpanName() from instrumentation-mysql2 was taking non-negligeable time from our profiler in production, considering that it's in a critical path.

This PR replaces split() by substring() to avoid instanciating a new array everytime.

Here is a benchmark with the difference before and after (~20 times faster for me): https://jsbm.dev/YtumA6nRNvjVJ

Short description of the changes

Use substring() with indexOf() instead of split() to extract the SQL verb from a sql query. It also checks for queries with no spaces like "COMMIT" and fallback to return the raw query.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: geotry / name: Geoffrey Thierry (aed3839, 81e955b, d0fae7c)
• ✅ login: david-luna / name: David Luna (868ed59)

[maryliag]

Would you mind doing the same change on the other mysql package, to keep consistency: https://github.com/open-telemetry/opentelemetry-js-contrib/blob/main/plugins/node/opentelemetry-instrumentation-mysql/src/utils.ts#L118

[github-actions]

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.53%. Comparing base (25ab243) to head (81e955b).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2470      +/-   ##
==========================================
- Coverage   90.74%   90.53%   -0.21%     
==========================================
  Files         156       99      -57     
  Lines        7723     5092    -2631     
  Branches     1588     1008     -580     
==========================================
- Hits         7008     4610    -2398     
+ Misses        715      482     -233     

Files with missing lines	Coverage Δ
...e/opentelemetry-instrumentation-mysql/src/utils.ts	97.82% <100.00%> (+0.09%)	⬆️

... and 57 files with indirect coverage changes

[david-luna]

@geotry

Thanks for contributing to OpenTelemetry :)

Could you run npm run lint:fix and push the changes to pass all checks?

[geotry]

thanks for the review

@maryliag I implemented the change in instrumentation-mysql and added tests to cover getSpanName().
I c/c the same code from instrumentation-mysql2 for consistency but it was slightly different as it was returning the full query string in case of an object instead of just the verb. I'm not sure wether it's safe or not to apply this change, let me know and I can revert it 👍

I also fixed the lint issues, sorry about that @david-luna