Add example and functors related to matching particles by VELO LHCbIDs

• Adds the ISBASICPARTICLE functor.
• Adds test for FlattenDecayTree and particle matching

Needs Rec!3385 (merged)

DaVinciExamples/python/DaVinciExamples/tupling/AllFunctors.py

@@ -151,6 +151,7 @@ def all_variables(pvs, dtf, mctruth, ptype, candidates=None, ftAlg=None):
 # duplicated from FC   all_vars.update({ 'ENERGY' : F.ENERGY})
     all_vars.update({'ETA': F.ETA})
     all_vars.update({'FOURMOMENTUM': F.FOURMOMENTUM})
+    all_vars.update({'ISBASIC': F.ISBASICPARTICLE})
 
     if basic:
         all_vars.update({'GHOSTPROB': F.GHOSTPROB})