Last main e/gamma feature before freeze : Make e vs gamma ambiguity more loose-> more ambiguous

• Last main feature change from e/gamma : https://indico.cern.ch/event/950349/contributions/3993448/attachments/2098996/3528539/slides.pdf slide 3.

• This MR changes the ambiguity resolution between electron and photon in egamma reconstruction. Detail are here (for example slide 33 (the title is wrong, should be photons)): https://indico.cern.ch/event/937428/contributions/3938359/attachments/2071086/3476869/slides.pdf

• With this MR some true photons that were wrongly classified as "for sure not photon" (and so saved only as electron in the xAOD) are classified as ambiguous (so saved both as electron and photon in the xAOD). So we expect more photons in the output.

Closes ATLASRECTS-4842 and should complete e/gamma features for the freeze.