add benchmark for pion0

benchmarks/clustering/scripts/cluster_plots.py

benchmarks/ecal/scripts/draw_cluters.py

benchmarks/imaging_ecal/config.yml

benchmarks/imaging_ecal/options/hybrid_cluster.py

benchmarks/imaging_ecal/options/imaging_2dcluster.py

benchmarks/imaging_ecal/options/scfi_cluster.py

benchmarks/imaging_ecal/run_imcal_pion0.sh

benchmarks/imaging_ecal/scripts/get_layerids.py

benchmarks/imaging_ecal/test_geo.xml