Add Lxy cut and monitoring to TrigMultiTrkComboHypo

We may need lxy0 triggers so I have added the ability to cut on lxy and added monitoring for lxy,

Decoration code will no longer be called during Dimu L2 trigger (since it wasn't used).

I now pass eventcontexts to the VKalVrt, this avoids a threadlocal lookup which can hurt performance.

Trigger/TrigHypothesis/TrigBphysHypo/python/TrigMultiTrkComboHypoConfig.py

@@ -111,5 +111,8 @@ class TrigMultiTrkComboHypoConfig(object):
         if 'noos' in chainDict['topo']:
             tool.totalCharge = -100 # negative number to indicate no charge cut
 
+        if 'Lxy0' in chainDict['topo']:
+            tool.LxyCut = 0.0
+
         tool.MonTool = TrigMultiTrkComboHypoToolMonitoring('MonTool')
         return tool