Process hub cleanup and build updates

[anomit]

Fixes #

Checklist

• My branch is up-to-date with upstream/develop branch.
• Everything works and tested for Python 3.8.0 and above.
• I ran pre-commit checks against my changes.
• I've written tests against my changes and all the current present tests are passing.

Current behaviour

The process hub core used to control the spawning and restarting of worker processes -- for eg those responsible for snapshot and aggregate computes.

This was removed in the last merge to main. But there were a few helpers and features that were not cleaned up.

Also, the local collector runs as its own binary now instead of being run as a pm2 managed process and docker-compose.yaml needs to be udpated for the same.

New expected behaviour

As described above.

Change logs

Changed

• Local collector docker container entry point

Removed

• Process hub core helper

Deployment Instructions

• To test in dev mode, use the source feature branch of this PR along with the dockerify branch of local collector.
• For non-dev mode, use dockerify branch of both snapshotter-core and local collector.

[xadahiya]

Tested on local and a staging server. LGTM! (after 9076960)