More improvements to SNMP MIB
Additional feedback from #24402:
It would be nice to have the alertLevel as an integer value, enumerating all of the possible levels (I imagine that's basically just "WARN, CRITICAL, NORMAL")
It would be very very nice to include some unique ID for an alert, so that we can correlate traps in upstream NMS systems.
With that, it would be awesome to have separate "clearing" alerts that come in, including the ID of the alert that is being cleared, when an alert is no longer active; that way, upstream NMS systems can automatically clear alerts on their own dashboards.
Similar to the alertLevel, the zpoolHealth should be an enumerated integer value, to make it easier for consumers to know all of the possible values, and to make it easier for upstream alerting systems to classify events.