- replace HltRawBankDecoderBase base class with a service and
  standalone utility funtions
- update decoder classes accordingly
- update the IIndexedANNSvc interface so that it can be used instead
  of the HltANNSvc to implement all int->string mappings.
  (as the interface is a 'versioned superset' of the HltANNSvc)
- update encoder and decoder classes accordingly
  NOTE: this included the ExecutionsReportWriter!
- replace use of non-thread-safe Error and Warning with MsgCounter