Daqd channel hash with broadcast

The broadcast daqds modify their channel list to mark only the broadcast channels as active/acquired. This is what they should do, but it means a straight hash of the channel list creates a different channel hash than the other daqds. This fix calculates the channel hash two ways, one w/o modification, and one w/ the broadcast list explicitly ignored. This will all the broadcast daqd to declare that it has the same base channel hash (before applying the broadcast list to the channel list) as other daqds and will allow gds broadcasters to have their broadcast list checked as well.

Move the hashing from the start main handler to the channels begin/end handler. Add a {PREFIX}CHANNEL_LIST_CHECK_SUM_BCAST pv to show the channel hash after processing for the broadcast list. On non-broadcast daqds these will be identical to the {PREFIX}CHANNEL_LIST_CHECK_SUM pv.