[v10r1] FTS3: add an LHCb plugin
This will be used by https://github.com/DIRACGrid/DIRAC/pull/5096 but can be merged before (actually, it must be merged if we release with the DIRAC PR).
It will spare us the hotfix for RAL, as it's now a plugin...
It currently runs on lbvobox303, and the CS is already configured accordingly
BEGINRELEASENOTES
*DMS
NEW: FTS3 LHCb plugin
ENDRELEASENOTES
Edited by Christophe Haen