Rename MCParticle relations to particle

Avoids clash with type-name

edm4hep.yaml

@@ -233,13 +233,14 @@ datatypes:
       - edm4hep::Vector3d position     //the hit position in [mm].
       - edm4hep::Vector3f momentum     //the 3-momentum of the particle at the hits position in [GeV]
     OneToOneRelations:
-      - edm4hep::MCParticle MCParticle //MCParticle that caused the hit.
+      - edm4hep::MCParticle particle //MCParticle that caused the hit.
     MutableExtraCode:
       includes: "#include <cmath>"
       declaration: "
       int32_t  set_bit(int32_t val, int num, bool bitval){ return (val & ~(1<<num)) | (bitval << num); }\n
       void setOverlay(bool val) { setQuality( set_bit( getQuality() , BITOverlay , val ) ) ;   }\n
       void setProducedBySecondary(bool val) { setQuality( set_bit( getQuality() , BITProducedBySecondary , val ) ) ;   }\n
+      void setMCParticle(edm4hep::MCParticle particle) { setParticle(std::move(particle)); }\n
       "
     ExtraCode:
       declaration: "
@@ -251,6 +252,7 @@ datatypes:
       double y() const {return getPosition()[1];}\n
       double z() const {return getPosition()[2];}\n
       double rho() const {return sqrt(x()*x() + y()*y());}\n
+      edm4hep::MCParticle getMCParticle() const { return getParticle(); }\n
       "
 
 
@@ -540,7 +542,12 @@ datatypes:
        - float pulseTime                     //the pulse's time in the lab frame [ns].
        - float pulseAmplitude                //the pulse's amplitude [fC].
     OneToOneRelations:
-      - edm4hep::MCParticle MCParticle       //the particle that caused the ionizing collisions.
+      - edm4hep::MCParticle particle       //the particle that caused the ionizing collisions.
+    MutableExtraCode:
+      declaration: "void setMCParticle(edm4hep::MCParticle particle) { setParticle(std::move(particle)); }\n"
+
+    ExtraCode:
+      declaration: "edm4hep::MCParticle getMCParticle() const { return getParticle(); }\n"
 
  #----------  TrackerPulse
   edm4hep::TrackerPulse: