Major step towards making Boole algorithms functional

Goes with LHCb!5375 (merged)

This is not the end of it, but in this step, all Boole algorithms still modifying the RawEvent (actually only HCDigitCreator) are changed so that they actually create their own RawEvent, hidden for the others and output a View on the interesting RawBanks. The different views are then be used to build the final RawEvent in the configuration.