LHCBGAUSS-1120: Tests for Em think layers and Brems

A new directory is added in the Sim/SimChecks/scripts called EmValidation_LHCbPR. This directory mainly contains scripts written by Pete and used for the EM tests. Most of the options files are a bit modified and new ones are added in order to store properly and with all relevant information the histograms that will be used for the moment from LHCbPR.

A small bug is found and fixed in Sim/GaussMonitor/src/BremVeloCheck.cpp. This bug was spotted by Pete and it had to do with the fact that the final histograms produced for the bream test were not filled with the proper information.