Draft: [Futurev5] RICH in DD4hep

This is a first version of the new GaussPhotonics package based on Gaussino and DD4HEP, for RICH simulation. It is based on the Futurev4 branch of Gauss. It creates G4Hits; however they are not yet copied to MCHit structure. An example of the options file used for running this with particle gun is attached. The pgun options are in some files in Gauss/Gen/LbPGuns/options area. This needs a version of the 'Detector' package that is at least a 'recent master version'; a better option is a 'master version' that is expected to be available in a few days. For reference, a log file obtained when running Gauss for a few events is attached. This new draft MR is made following a recent suggestion from @mimazure . This Draft MR replaces Draft MR !817 (closed) . Gaussino-example-run-options.py.txt Gauss-example-run.log.txt