Decommissioning of COOL

See merge requests !1638 (merged) !1401 (merged)

(cherry picked from commits 6a88a678 588b2aa6)

As is, this MR does not compile without gaudi/Gaudi!759 (merged), but it's not mandatory to compile with Gaudi master, so we can apply it in a second stage.

See LHCBPS-1836