test_runner: add parentId to test events with testId

[MoLow]

Add parentId to the test:enqueue, test:dequeue, test:start,
test:complete, test:pass, and test:fail event payloads. It carries
the enclosing test's testId (or undefined for top-level tests).

Custom reporters need explicit parent linkage to track lineage when
concurrent siblings at the same nesting level interleave their events —
a shared ancestors stack records the wrong parent for every failing leaf
under siblings whose bodies yield before calling t.test(), and the
output tree collapses them to one entry.

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.05%. Comparing base (4ee7567) to head (548f144).
⚠️ Report is 20 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #63435   +/-   ##
=======================================
  Coverage   90.05%   90.05%           
=======================================
  Files         714      714           
  Lines      225876   225926   +50     
  Branches    42737    42739    +2     
=======================================
+ Hits       203408   203466   +58     
- Misses      14244    14250    +6     
+ Partials     8224     8210   -14     

Files with missing lines	Coverage Δ
lib/internal/test_runner/test.js	97.03% <100.00%> (+<0.01%)	⬆️
lib/internal/test_runner/tests_stream.js	89.00% <100.00%> (+0.34%)	⬆️

... and 43 files with indirect coverage changes

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[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/73570/