add support for TH3 reading from conditions DB

Redo of !3112 (merged), which was reverted via !3207 (merged)
But now wait for Gaudi release that includes gaudi/Gaudi!1226 (merged)

Adds TH3 support for use with CondDB. Needs gaudi/Gaudi!1226 (merged) and needed for Rec!2319 (merged).

fyi: @mveghel