Process Actor Refactor

[jordan-rash]

Will close #464

[bruth]

The PR is still in draft, but looks good in the current state.

[github-actions]

Merging this branch will increase overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/synadia-io/nex/node/internal/actors	12.45% (+0.10%)	👍

---

Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/synadia-io/nex/node/internal/actors/direct_start_agent.go	12.44% (ø)	201	25	176
github.com/synadia-io/nex/node/internal/actors/os_procs.go	0.00% (ø)	34	0	34
github.com/synadia-io/nex/node/internal/actors/process_actor.go	0.00% (ø)	107 (-8)	0	107 (-8)

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.