ci: transcribe cjs tests to ES Modules and TypeScript

[wellwelwel]

Continues the work from #4086 by migrating all tests to ES Modules + TypeScript 🎉

Since this is so intensive, I'll break it down into stages. This PR will be exclusive for migrating the tests, not for refactoring them or deleting the .cjs files.

☔️ To be able to "navigate" through so many files and ensure there were no losses, I relied on coverage ratio.

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As with #4086, no files outside tests were modified. Until the third stage, .cjs files will be kept (without any use) to assist in refactoring and to provide an accurate comparison to the original tests.

• There are 157 missing types mapped that went unnoticed by ./test/tsc-build 😵‍💫
  • By searching for // @ts-expect-error: TODO: implement typings throughout the tests, fixes should be applied directly to the actual MySQL2 types.

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Related

• Improve contributors and users experience #3695

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Off the record, I need to say that this really took a lot of work 🥲

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.95%. Comparing base (d830838) to head (a00f22b).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4091   +/-   ##
=======================================
  Coverage   89.95%   89.95%           
=======================================
  Files          86       86           
  Lines       13663    13663           
  Branches     1637     1637           
=======================================
  Hits        12291    12291           
  Misses       1372     1372           

Flag	Coverage Δ
compression-0	89.07% <ø> (ø)
compression-1	89.93% <ø> (ø)
static-parser-0	87.54% <ø> (ø)
static-parser-1	88.30% <ø> (ø)
tls-0	89.36% <ø> (ø)
tls-1	89.73% <ø> (ø)

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[wellwelwel]

In the third step, I'll remove all unused files (.cjs) and include a dedicated section for tests in the documentation (probably in Contributing.md).