fix(expect): throw if expect.hasAssertion and expect.assertions are not checked

[WWRS]

fixes #6518
fixes #6540

• Renamed AssertionState to AssertionCounter
• Moved AssertionCounter from std/internal to std/expect: It's really more of an expect feature than an internal feature
  • This means that std/testing now depends on std/expect
• Removed AssertionCounter.#state.assertionTriggered to avoid desynchronizing from assertionTriggeredCount
• Collected the validation error behavior in AssertionCounter rather than duplicating it in testing
• Ensured AssertionState is reset after validation: fixes expect.hasAssertion and expect.assertions pollute other assertions tests #6540
• Added a cleanup step when globalThis is unloaded to ensure all AssertionStates are properly validated and reset: fixes expect.hasAssertion and expect.assertions silently pass outside bdd tests #6518

[codecov]

Codecov Report

Attention: Patch coverage is 67.50000% with 13 lines in your changes missing coverage. Please review.

Project coverage is 94.81%. Comparing base (c338b2f) to head (eedc630).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/assertion_state.ts	41.66%	7 Missing ⚠️
testing/_test_suite.ts	57.14%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6646      +/-   ##
==========================================
+ Coverage   94.75%   94.81%   +0.06%     
==========================================
  Files         584      574      -10     
  Lines       46563    46439     -124     
  Branches     6541     6528      -13     
==========================================
- Hits        44120    44032      -88     
+ Misses       2400     2364      -36     
  Partials       43       43              

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[kt3k]

Thank you for the PR! This looks like a nice fix, but I left some comments about code organization.