Don't parse RTDL packets

Removed the code for parsing the RTDL packets.  Also removed the code in
the BankedEventPkt parser that checked the pulse ID on the RDTL packets.

Refs #6932
Merge remote branch 'origin/feature/6932_Ignore_RTDL_Packets'

Re #6932.
Conflicts:
	Code/Mantid/Framework/DataHandling/src/SNSLiveEventDataListener.cpp