switch zone setup should be interruptable #9182
Description
When a sidecar goes away, we need to tear down the switch zone in under a minute to ensure that illumos can cleanly remove the tofino device driver. Failure to do so can leave us in a state where the tofino asic won't be properly reinitialized when the sidecar reappears, and will require the scrimlet to be rebooted.
Right now, when the HarwareMonitor kicks off an oxz_switch zone setup, it will run to completion before we reconsider whether the switch zone should be running at all. In general this is fine, but we need a mechanism to interrupt this setup if the sidecar disappears while it is in process to allow for a timely zone shutdown.