Migrate away from using (3 value) RICH RadiatorArray to (2 value) DetectorArray

( Note, branch here is based off of !4676 (merged) so that should be merged first. )

Requires Detector!639 (merged)

Migrate away from using the 3 value RadiatorArray, which implies the unused baggage of the first unused entry for Aerogel, to DetectorArray with a single entry for each RICH.

e.g., allows this

# First entry is always ignored ... Next are Rich1Gas, Rich2Gas
alg.RadValues = ( 0, 1, 2 )

to be streamlined to

# Values are Rich1Gas, Rich2Gas
alg.RadValues = ( 1, 2 )

One last comment. You might wonder why not entirely remove the Rich::Aerogel enum type and instead just have the Rich1Gas and Rich2Gas enums, and reduce the RadiatorArray down to only 2 values at the C++ level. The problem with this is that would mean the numerical values for the Rich1Gas and Rich2Gas enums would change, from 1 and 2 respectively, to 0 and 1. The current values have, for better or worse, found their way into a number of persistent locations (SIM,DIGI,DST) files and thus changing these labels now will just cause a major headache. This is why I instead intend to keep the values as they are, and instead migrate any usage of the RadiatorArrays to DetectorArrays, which are accessed with a different enum label (Rich1 and Rich2) the values for which are, and always have been, 0 and 1.

Kernel/LHCbKernel/include/Kernel/RichDetectorType.h

@@ -39,16 +39,25 @@ namespace Rich {
    *  @param detector RICH detector enumeration
    *  @return Detector type as a string
    */
-  std::string text( const Rich::DetectorType detector );
+  std::string text( const DetectorType detector );
 
   /// Implement textual ostream << method for Rich::DetectorType enumeration
-  inline std::ostream& operator<<( std::ostream& s, const Rich::DetectorType& detector ) {
-    return s << Rich::text( detector );
+  inline std::ostream& operator<<( std::ostream& os, const DetectorType& detector ) {
+    return os << Rich::text( detector );
   }
 
   /// Print a vector of Detector IDs
-  inline std::ostream& operator<<( std::ostream& str, const Detectors& dets ) {
-    return GaudiUtils::details::ostream_joiner( str << '[', dets, ", " ) << ']';
+  inline std::ostream& operator<<( std::ostream& os, const Detectors& dets ) {
+    return GaudiUtils::details::ostream_joiner( os << '[', dets, ", " ) << ']';
   }
 
+  /// Print contents of a DetectorArray templated type
+  template <typename TYPE>
+  inline std::ostream& operator<<( std::ostream& os, const DetectorArray<TYPE>& dets ) {
+    return GaudiUtils::details::ostream_joiner( os << '[', dets, ", " ) << ']';
+  }
+
+  /// Convert RICH enum to Radiator enum
+  inline auto radType( const DetectorType rich ) { return ( Rich1 == rich ? Rich1Gas : Rich2Gas ); }
+
 } // namespace Rich