Rationalize PC job control states for NiFi

Pipeline Controller provides buttons for controlling jobs (stop, fail, abandon). These don't really affect the NiFi flow. I believe these only change the pipeline controller job repository.

We need to think through the various states, how it will affect NiFi if at all and what it means.

Stop - should use the NiFi REST API to halt the entire process group. This does not make sense for a single job, only the feed-level. Another option is to not show this option at all and expose "stop" from the scheduler?

Fail - result of an unsuccessful flow. I don't know if we should allow users to set this state.

Abandon - abandon might be something we expose after a job fails. It will update job repository as abandon and no longer show up as "Unhealthy" for the feed.

Migrate from: PC-78