PDI-11582: Add initial hdp21 shim
[PDI-11582]: Updated hdp21 Ivy deps for HBase
[PDI-11582]: Fixed ivy dependencies for Xerces
PDI-11582 - Add default location for MR's jobhistory server
[PDI-11582] added  HDP21 to the list of modules needed to build
[PDI-11582] Support cross-platform MR jobs