ERP5Workflow: perf: support parameter 'state' in isActionSupported

This allows to avoid the call of _getWorkflowStateOf if it was already
done before, and so reduce the number of calls of '_getOb' method.

product/ERP5Workflow/Document/Workflow.py

@@ -173,14 +173,16 @@ class Workflow(IdAsReferenceMixin("", "prefix"), XMLObject):
     return 0
 
   security.declarePrivate('isActionSupported')
-  def isActionSupported(self, document, action, **kw):
+  def isActionSupported(self, document, action, state=None, **kw):
     '''
     Returns a true value if the given action name
     is possible in the current state.
     '''
+    if state is None:
       state = self._getWorkflowStateOf(document, id_only=0)
       if state is None:
         return 0
+
     if action in state.getDestinationIdList():
       transition = self._getOb(action, None)
       if (transition is not None and