LPS-42397 Add staged model data handler to support DDLRecord export/import
LPS-42397 Register SMDH
LPS-42397 Add DDLRecord support to DDLPortletDataHandler
LPS-42397 Propagate system events when deleting records
LPS-42397 Fix missing system events when deleting DDLRecordSets
LPS-42397 Add test
LPS-42397 Source format - no logic changes
LPS-42397 Lang key
LPS-42397 SF
LPS-42397 Lang keys