LPS-34081 Change PDC to allow to export and reference not just StagedModel instances
LPS-34081 Apply PDC changes
LPS-34081 Add SMDH's skeletons and copy&paste existing code into them
LPS-34081 Change SMDH's to follow the new staging pattern
LPS-34081 Apply changes to JPDH
LPS-34081 Apply changes to JCPDH
LPS-34081 Register SMDH's
LPS-34081 Apply changes
LPS-34081 Fix broken DDM key references maps
LPS-34081 Fix wrong portlet preference key which caused staging bug when non-default article template
LPS-34081 Update DL reference handling based on recent DL changes