feat: reuseWorker strict mode

[toyobayashi]

https://emscripten.org/docs/tools_reference/settings_reference.html#pthread-pool-size

instantiateNapiModule({
  /**
   * equivalent to { size: 0, strict: false }
   */
  reuseWorker: true,

  reuseWorker: {
    size: 4, // equivalent to emscripten's PTHREAD_POOL_SIZE
    strict: true // equivalent to emscripten's PTHREAD_POOL_SIZE_STRICT=2
  }
})

If size > 0, only asynchronous loading API (instantiateNapiModule / loadNapiModule) can guarantee thread pool ready before emnapi initialization.

[toyobayashi]

nodejs/node#53036