Add times to MCVPDigit and HV and bad pixels to DeVPSensor to update VP simulation

These are the necessary changes in LHCb to implement the changes to VP simulation detailed in the talk in the simulation meeting (17th March 2020): https://indico.cern.ch/event/875982/

These add a parameter to MCVPDigit.h (check there is not an GOD XML file somewhere I need to also change), and code to read the HV and possible bad chips and pixels from CondDB to DeVPSensor. These changes should be synced with changes to LHCb (in dhcroft-NewVPSimTiming) and Digi to be submitted soon.

The linked changes are (all branches are called dhcroft-NewVPSimTiming): lhcb-conddb/DDDB!37 (merged) lhcb-conddb/SIMCOND!83 (merged) LHCb!2473 (merged) !453 (merged) Boole!271 (merged)