[ATR-22697] Add ModeOR and EnableOverride flags to ComboHypoTool base

If a trigger is applying isolation, it may want ALL combinations of objects between legs to be well isolated.

We add a new flag modeOR which defaults to True. In OR mode, any passing combinations will accept the event. In AND mode, all combinations will be required to pass for the chain to accept the event.

In addition, it is possible in the future that a chain is added which is capable of generating huge numbers of combinations. We already have CombinationsThresholdWarn and CombinationsThresholdBreak, but these are more to spot issues. We don't want chains regularly triggering these.

An EnableOverride flag is added which defaults to False. It can only be used in OR mode. If the flag is set then the loop over combinations will be exited upon the 1st valid combination. This is maximally CPU efficient, but we may fail to identify all Decision Objects which were part of a valid combination. This could be an issue if a) the ComboHypoTool isn't in the chain's final step or b) these data are used offline in physics analysis (matching) for the chain. So it should be used with caution.

Trigger/TrigSteer/DecisionHandling/DecisionHandling/ComboHypoToolBase.h

@@ -28,6 +28,8 @@ class ComboHypoToolBase : public extends<AthAlgTool, IComboHypoTool> {
 public:
   ComboHypoToolBase(const std::string& type, const std::string& name, const IInterface* parent);
   
+  virtual StatusCode initialize() override;
+
   /**
    * @brief retrieves the decisions associated to this decId, make their combinations and apply the algorithm
    * @param[in]  LegDecisionsMap that lists all the passing decisions, to be updated by the tool depending on the outcome of executeAlg 
@@ -108,6 +110,12 @@ public:
 
   Gaudi::Property<size_t> m_combinationsThresholdBreak {this, "CombinationsThresholdBreak", 10000,
     "Events processing this many combinations will generate a second WARNING message, and the loop over combinations will be terminated at this point."};  
+
+  Gaudi::Property<bool> m_modeOR {this, "ModeOR", true,
+    "Accepts based on the logical OR over all calls to executeAlg. If this flag is set to false then the logical AND is required instead."}; 
+
+  Gaudi::Property<bool> m_enableOverride {this, "EnableOverride", false,
+    "Stops processing combinations as soon as a valid combination is found in OR mode, or as soon as an invalid combination is found in AND mode. This is to save CPU."}; 
  
   // TODO - add optional write out of the data stored in passingCombinations in the decide function.