reshape switchOn and switchOff argument for ics_dcbActor

ics_dcbActor controls the arc lamps.

Currently, we were controlling them independently, passing one arc lamp at a time.

But passing a list of lamp would be more flexible, and actually not that hard.

spsait  (which command dcbActor)  would also need an update.

One expose command would be :

spsait expose exptime=20.0 switchOn=hgar,neon