Make DTrace share common functions

[leftwo]

Let me see if I can find an easier way.. in a follow up commit :)

Originally posted by @leftwo in #1773 (comment)

Can we share some common function between all or many of the DTrace scripts, without too much insanity?

[leftwo]

Specifically, this chunk:

/*
 * Translate the longer state string into a shorter version
 */
inline string short_state[string ss] =
    ss == "Active" ? "ACT" :
    ss == "WaitQuorum" ? "WQ" :
    ss == "Reconcile" ? "REC" :
    ss == "LiveRepairReady" ? "LRR" :
    ss == "New" ? "NEW" :
    ss == "Faulted" ? "FLT" :
    ss == "Offline" ? "OFL" :
    ss == "LiveRepair" ? "LR" :
    ss == "Replacing" ? "RPC" :
    ss == "Replaced" ? "RPL" :
    ss == "Disabled" ? "DIS" :
    ss == "Deactivated" ? "DAV" :
    ss == "NegotiationFailed" ? "NF" :
    ss == "Fault" ? "FLT" :
    ss;

@bnaecker had the idea to look at what OPTE does
https://github.com/oxidecomputer/opte/tree/master/dtrace