[CII-SR-450] - Only one buyer identifier should be present (either the ID or the Global ID)
Stored validation assertion
(not(ram:BuyerTradeParty/ram:ID) and ram:BuyerTradeParty/ram:GlobalID) or (ram:BuyerTradeParty/ram:ID and not(ram:BuyerTradeParty/ram:GlobalID)) or (not(ram:BuyerTradeParty/ram:ID) and not(ram:BuyerTradeParty/ram:GlobalID))