suggest new status codes

[shawndwells]

Adds new status codes:

inherited: such as physical controls being inherited when running on a FedRAMP IaaS

not applicable: added to align with FedRAMP documentation options, shows control is N/A. For example program management controls for a technology component.

unknown: suggest as default return for elements missing implementation_status

unsatisfied: knowingly unable to meet control

[shawndwells]

at some point there are many new schema elements to redo/introduce, but making this minor change seemed reasonable for a v3.1.1 schema update

[aegershman]

I realize this particular thread might be dead, but I'd like to suggest that if a status code of "not applicable" is introduced, I'd like to +1 suggest the use of either not_applicable or not-applicable, i.e. using a separator which isn't a space.

It's more conductive to automation which would use the status codes somehow (I don't have an example usecase, but it's generally valuable to be skeptical of whitespace), less to futz with for systems that implement spaces differently... And most importantly it's more ✨ aesthetically pleasing ✨

that's all 👍