updated consolidated recommendations for egamma calibration for es2017_R21_v1 model
- updated energy resolution parameterization
- added extra pileup related systematics on energy scale (few 10**-4) and energy resolution (up to few 10**-3)
- new systematics on energy resolution for AF2 to cover approximatively the AF2-FullSim differences that cannot be correctly compensated by change in smearing correction