add AATTChannelSpecSet
readonly, not nonatomic
add AATTTargetWithActionChannelsSpecSet

this defines a use case for the ChannelSyncManager - one target channel with 1 or more action channels
import AATTTargetWithActionChannelsSpecSet.h
deliver channel sync manager results with AATTChannelRefreshResultSet
add “regular” channel initialization functionality
fetch newest messages for “regular” channels