Deduce bank type from sourceID
Currrently, bank types in the MDF and MEP InputProviders are deduced from the bank type of the first bank. This will fail if the first bank is for example an error bank. The first five bits of the sourceID identify the sub-detector, therefore the sourceID should be used instead of the bank type. For MDF input files this does not work, as the MC does not encode the sub-detector in the sourceID at present. The sourceID is modified to contain the sub-detector bits when creating the MEP file from an MDF using Markus' application. Therefore, only the MEPProvider should be changed for now.