* Tool: Bring back mergefreeze API integration
Context: https://github.com/fleetdm/fleet/pull/5628#issuecomment-1196175485
Unfortunately, the API doesn't work.
* Lay out how this would work in the database - but instead, do it ephemerally for now
* Remove model
* Maintain state (the easy way for now)
* trivial (comments)
* Remove old unfreeze/freeze logic
* trivial (clarify comment)
* Trivial (fix weird character)
* Extrapolate DRI mappings into config.
* Explain why this exists
* Extrapolate logic
* Use extrapolated logic + add 5 second wait time to prevent accidents + clean up
* Use extrapolated logic and fix omission in helper
* Make freezing actually happen and document usage
* In script, don't freeze PRs as long as they're preapproved to be edited by SOMEBODY
* Lint fixes
