process: simplify the setup of async hooks trace events

- Remove `trace_category_state` from `Environment` - since this is
  only accessed in the bootstrap process and later in the
  trace category update handler, we could just pass the initial
  values into JS land via the trace_events binding, and pass
  the dynamic values directly to the handler later, instead of
  accessing them out-of-band via the AliasedBuffer.
- Instead of creating the hooks directly in
  `trace_events_async_hooks.js`, export the hook factory and
  create the hooks in trace category state toggle.

PR-URL: https://github.com/nodejs/node/pull/26062


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>