Merge remote-tracking branch 'origin/tf_ls'

cmdline/CtaAdminCmd.cpp

cmdline/CtaAdminCmdParse.hpp

cmdline/CtaAdminTextFormatter.cpp

cmdline/CtaAdminTextFormatter.hpp

xroot_plugins/CMakeLists.txt

xroot_plugins/GrpcClient.cpp

xroot_plugins/GrpcClient.hpp

xroot_plugins/GrpcEndpoint.cpp

xroot_plugins/GrpcEndpoint.hpp

xroot_plugins/Namespace.hpp

xroot_plugins/XrdCtaTapeFileLs.hpp

xroot_plugins/XrdSsiCtaRequestMessage.cpp

xroot_plugins/XrdSsiCtaRequestMessage.hpp

xroot_plugins/XrdSsiCtaServiceProvider.cpp

xroot_plugins/XrdSsiCtaServiceProvider.hpp

xroot_plugins/cta-frontend-xrootd.conf

xrootd-ssi-protobuf-interface