bhyve (and jails) manageability workstream

There is a collection of desired features for bhyve.

As of 2023/11, priorities appear to be on

1. state management daemon: possibly including a kernel component; Jan B is working on a draft for this, but code is not ready to be shared
2. redesign of snapshot and restore functionality as precursor to live migration capability

There is also some additional tooling to help construct better overall bhyve management tooling

• mk-epair.sh helper script for managing epairs (useful for vnet jails)