Generic exec.Command() posture checks

[nmcsween-nh]

Is your feature request related to a problem? Please describe.
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]

Currently posture checks are limited in what they can do.

Describe the solution you'd like
A clear and concise description of what you want to happen.

Add exec.Command() posture check and migrate the other bespoke ones as bundled executables.
The process, etc posture check can then just be a bundled go exe that gets called.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

The default posture checks.

Additional context
Add any other context or screenshots about the feature request here.