Create SmarActPicoscale subclass for OL-MDL positioners

[aberges-SLAC]

Current Behavior

Currently, the OL-MDL in FTL are run in SmarAct typhos screens, which lack important PVs related to the Picoscale (PS) interferometer & sensor heads that actually dictate the

Expected Behavior

Be able to read PS related RBV on device state, PS state, working distances, etc.

Context / environment

Useful for OL-MDL in the FTL and other potential deployments of SmarAct Picoscale systems.

Suggested Solution

Subclass the SmarAct device class in pdsdevices.epics_motor and include the necessary PVs.