Iso photons

This MR is to write out the isolated photons at HLT in a separated container. The logic is the following:

• PrecisionPhoton stage creates xAOD photons
• PrecisionPhotonCaliIso pick up those photons as input and:
  • create a new Output Container HLT_egamma_Iso_Photons
  • copy there the input photons
• Run the isolation tool on the new created output container which decorates them
• apply hypothesis

Inside Trigger/TrigHypothesis/TrigEgammaHypo/src/TrigEgammaPrecisionPhotonCaloIsoHypoAlg.cxx:

• Output collection is created at initialize (key configured via properties)
• in execute loop when looping over input container, photons are copied over the output container and on them the HypoTool, which cals the isolation tool and decorate the photons on which the hypothesis requirement is applied

This is expected to fix ATR-26332

Pinging @safarzad @eegidiop and @dbakshig