Allow to take into account grand parents in ClusterEfficiency algorithm
Use grandparents to allow selection of pi0 when running ClusterEfficiency.
This MR is required for a Moore MR Moore!1498 (merged) that implements new calo efficiency counters based on pi0.
The code was developed by @aszabels. I've rebased it on master and updated where needed.
Edited by Konrad Klimaszewski