HLT Prescale provider and client
Implements the HLTPrescaleCondAlg to provide the HLT prescales (either from file, db, or cool+db). Also implements the L1Decoder::PrescalingTool as a client for the prescales. Note that the client does disable or enable (default enable) all chains in case a prescales set is missing.
At the moment the client is not enabled, as we need a consistent configuration for the condAlg (see ATR-20546) Tracked in ATR-19245.