Channel access vs. PVA

[nneveu]

Is your feature request related to a problem? Please describe.
We are currently using channel access through PyEpics. Due to security concerns, channel access may be going away in the next two years at SLAC. We should look at switching to PVA if possible or investigate whether PyEpics developers are going to update the PyEpics PV class to use PVA instead of channel access.

Describe the solution you'd like
Use a different class for PVA vs. the PyEpics PV class.
This applies to devices that call PVs, for example magnets.

Or confirm that PyEpics developers will update PV class to use PVA vs. channel access.

Describe alternatives you've considered
Alternative is channel access goes away at SLAC in a year or two and we can not use devices in lcls-tools anymore.

Additional context
Might be a good issue for support from RadiaSoft.