pfilampsActor should actively query for gen2 telescope status

The pfilamps actor will not allow lamps to be turned on if the dome shutter is not closed. But it currently does not query for updated values itself: it depends on the caller to do that.

Wrong. The pfilamps controller needs to actively call gen2 updateTelStatus before rejecting a lamp command.

Note: the pi flashes lamps on prepare to check whether they are alive. This is why we reject prepare commands and not just go commands.