Improve ElectronPhotonFourMomentumCorrection tests in rel21 as in rel22
requested to merge ATLAS-EGamma/athena:improve_ElectronPhotonFourMomentumCorrection_test_rel21_asrel22 into 21.2
In the MR the tests for the PhysicsAnalysis/ElectronPhotonID/ElectronPhotonFourMomentumCorrection package are aligned to the ones in rel22, in particular testing the latest recommendations 2018_R21_v0
This MR does not change the behaviour of the tool, but only the tests.
This MR is a cherry pick from MR !47985 (merged) using MR commit 8a106766 plus some changes to make it compatible with rel21.
This MR is important since we want to be sure that when updating PhysicsAnalysis/ElectronPhotonID/ElectronPhotonFourMomentumCorrection with the latest recommendation for rel21 we don't have any regressions.
All the tests are passing.
This closes ATLASEG-247