[EMCAL-1157] Update clusterizer algorithm to use relative time window…

[mhemmer-cern]

… always relative to seed cell

• Update clusterizer algorithm to use relative time window always relative to seed cell instead of the current cell during clusterization. So right now when looking for another cell to add to the cluster the relative time check is always done in respect to the time of the new cell and the cell from which this new cell would be added (so +-1 in eta or +-1 in phi direction). Most clusters arent that big and thus this change should only have minor consequences to the resulting clusters.