src: elevate v8 namespaces for node_process.cc

Elevate namespace for repeated entities.
Resolved conflicts.

PR-URL: https://github.com/nodejs/node/pull/24578


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>