feat(perf): offload generators to worker threads

[avivkeller]

Description

This PR offloads generators to worker threads. I've done a check of each generator, and nothing crashes, however, please please do a run through to verify nothing changed.

Because some functions cannot be cloned, toString() (on SemVer) has been replaced with .version, and similar for other SemVer related activities.

Validation

The output should be identical to the current generation.

Related Issues

See https://openjs-foundation.slack.com/archives/CVAMEJ4UV/p1744161814523689

Check List

• I have read the Contributing Guidelines and made commit messages that follow the guideline.
• I've covered new added functionality with unit tests if necessary.

[AugustinMauroy]

LGTM

[ovflowd]

Mostly LGTM! But could you add benchmarks (simple time would suffice with different amount of threads) to check how much perf we gaining here.

[avivkeller]

For the following command:

node ./bin/cli.mjs -i ../node/doc/api/*.md -t legacy-json -t legacy-html -o out

Where "Benchmark 1" ran with worker support, and "Benchmark 2" ran without:

Benchmark 1:
  Time (abs ≡):        47.460 s               [User: 95.622 s, System: 2.748 s]

Benchmark 2:
  Time (abs ≡):        68.457 s               [User: 77.903 s, System: 1.420 s]

Benchmark 1 is 1.44 times faster than than Benchmark 2