Added ArchiveRequest cancellation

common/dataStructures/DeleteArchiveRequest.cpp

common/dataStructures/DeleteArchiveRequest.hpp

objectstore/Sorter.cpp

scheduler/OStoreDB/OStoreDB.cpp

scheduler/OStoreDB/OStoreDB.hpp

scheduler/OStoreDB/OStoreDBFactory.hpp

scheduler/Scheduler.cpp

scheduler/SchedulerDatabase.hpp

...ver/castor/tape/tapeserver/daemon/DataTransferSession.cpp

...r/castor/tape/tapeserver/daemon/MigrationTaskInjector.cpp

...rver/castor/tape/tapeserver/daemon/RecallTaskInjector.cpp

tapeserver/castor/tape/tapeserver/daemon/TaskWatchDog.hpp

xroot_plugins/XrdSsiCtaRequestMessage.cpp