Added drive --comment and --reason fields in the objectstore

cmdline/CtaAdminCmdParse.hpp

common/dataStructures/DesiredDriveState.cpp

common/dataStructures/DesiredDriveState.hpp

objectstore/DriveState.cpp

objectstore/cta.proto

scheduler/OStoreDB/OStoreDB.cpp

scheduler/OStoreDB/OStoreDBTest.cpp

scheduler/Scheduler.cpp

scheduler/Scheduler.hpp

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

...castor/tape/tapeserver/daemon/DataTransferSessionTest.cpp

tapeserver/daemon/DriveHandler.cpp

xroot_plugins/XrdCtaDriveLs.hpp

xroot_plugins/XrdSsiCtaRequestMessage.cpp

xroot_plugins/XrdSsiCtaRequestMessage.hpp

xrootd-ssi-protobuf-interface