async_hooks: add trace events to async_hooks

This will allow trace event to record timing information for all
asynchronous operations that are observed by async_hooks.

PR-URL: https://github.com/nodejs/node/pull/15538


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>