Prefer explicit `put(unique_ptr<T>)` over of `put(T*)`

Stop using the to-be-deprecated (and to-be-removed) put(T*) -- see gaudi/Gaudi!1086 (merged) -- and prefer the (already existing for long) put(std::unique_ptr<T>).

This fixes the three remaining instances which were overlooked in !2625 (merged)...