Add parent and variations fields to Channel
Added Platform and Region as separate classes extending ChannelGroup, rather than typed instances of ChannelGroup
Remove ChannelGroupType from ChannelGroup
Add ChannelNumbering, which links a Channel to a ChannelGroup via a channel number.
Also added references to ChannelNumberings into Channel, so can find a Channel's numbers from the Channel object
Change references to Channels/ChannelGroups to Longs. Add ChannelGroupType, which is an Enum of the types of ChannelGroup, purely for persistence.
Correct equals() implementation for ChannelNumbering
Add start/endDates to image and title fields for Channel/ChannelGroup, as well as to
Channels and ChannelNumberings. Adjust simple model to output new fields.
Merge branch 'mbst-4019-ingest-pa-channel-data' into stage