Refactored WriterGroupPublishState out of IPubSubConnection file
JSON Discovery messages for DataSetMetaData
UADP Discovery messages for DataSetMetaData (Request + response)
Refactored the UaPublisher, extracted IntervalRunner and reused it in UdpDiscoveryPublisher & UdpDiscoverySubscriber
Proposal: automatic setting of ConfigurationVersion based on the rules in 6.2.2.1.5 (part 14)in new class Opc.Ua.PubSub.Configuration.ConfigurationVersionUtils
New events added to UaPubSubApplication
Implemented support for UADP Data Key Frame DataSetMessages
Unit tests were updated to cover the new functionality