State.py: add variable type_list to store value state_type from property.

product/ERP5Workflow/Document/State.py

@@ -52,6 +52,7 @@ class State(IdAsReferenceMixin("state_", "prefix"), XMLObject, XMLMatrix):
   isRADContent = 1
   erp5_permission_roles = {} # { permission: [role] or (role,) }
   default_reference = ''
+  type_list = ()
   # Declarative security
   security = ClassSecurityInfo()
   security.declareObjectProtected(Permissions.AccessContentsInformation)