src: use V8 graph heap snapshot API

Transition to a newer, more flexible API for
heap snapshot creation.

This addresses a currently pending deprecation in the V8 API.

PR-URL: https://github.com/nodejs/node/pull/21741
Fixes: https://github.com/nodejs/node/issues/21633


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>