Validate new code for ecal barrel<->endcap links

[giovannimarchiori]

For @varnes: we need to validate the modifications to the ecal barrel<->endcap neighbours (updates in the lookup initialisation) introduced by #199

After that (for @giovannimarchiori): create a PR to remove commented code in CreateFCCeeCaloNeighbours if it is confirmed that some of the vectors are not needed