Revise photon PID cuts

The photon PID cuts are too tight (even under good conditions, and definitely knowing that there are some problems with the ECAL) https://indico.cern.ch/event/1495991/#preview:5316296

• Cut IsNotH>0.2 and IsPhoton>0.2 for all radiative lines
• Remove E19 cut as it complicates calibration while being very strongly correlated with PID variables
• To combat large (~25%) increase in bandwidth, cut photon pT > 3GeV
• Use the same builder make_rad_photons for all lines in b_to_xgamma_exclusive. rad_incl and baryonic_radiative lines can then apply tighter selections on top if desired by modifying rad_incl_photons and make_rad_baryonic_photons builders
• Move converted photon builders from rad_incl_builder to b_to_xgamma_exclusive_builders