report: add support for Workers

Include a report for each sub-Worker of the current Node.js instance.

This adds a feature that is necessary for eventually making the report
feature stable, as was discussed during the last collaborator summit.

Refs: https://github.com/openjs-foundation/summit/pull/240

PR-URL: https://github.com/nodejs/node/pull/31386


Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>