Add truth entries for e/gamma, would possibly allow to have this running in Q221

Add truth entries for e/gamma objects.

Could allow to have them monitored for Q221 during the 1st experimental phase. (Q431 does not have truth so prb we do not want to monitor e/gamma there yet)

Obviously most of the electrons in Q221 and half the photons are fakes i.e no real photons (guess neutral pion can decay) or electrons (as anticipated) , not sure we want to keep the fakes. But this has been discussed in length on the context of total being fakes mainly today so ,...

I guess if we keep fakes for now , then it will depend on how often updates will happen for "fakes" reason. Then perhaps we can be informed for Q431 and if want to turn e/gamma on there ...

Mentioning @wlampl , @emoyse , @turra , @amete ,@nicolaid , @jmaurer , @jpoveda

PS : indirectly checks for broken truth links as what is attached to electrons is the one that was attached to the InDetTrackParticle associated to it, and changes to best match track (that could change also this).