MCParticle opt-in to (subset of) ThOr functors, use SIMDWrapper types as early as possible
add threeMomentum, fourMomentum, referencePoint and mass2 to allow ThOr functors to access some of the content of MCParticle -- and update all implementation of those functions to run SIMDWrapper types
also see Rec#223
must be applied in conjunction with Rec!2668 (merged)
Edited by Gerhard Raven