Add Functionals: PhotonMaker and MergedPi0Maker
Add 2 Gaudi::Transformers that adapt PhotonMaker and MergedPi0Maker to upgrade framework
FunctionalPhotonMaker adapts PhotonMaker ensuring thread-safety during execution.
FunctionalMergedPi0Maker adapts MergedPi0Maker, that now inherits from the FunctionalPhotonMaker class (instead of a basic pi0 maker class) to avoid code repetition. It also ensures thread-safety during execution.
A corresponding class for Resolved pi0s has not been included, as it looks like using particle combiner to combine 2 photons provides the same result. This has been tested in the context of Moore, which has a related MR to make use of these new functionals (Moore!593 (merged))
Edited by Alejandro Alfonso Albero