Support Access Dimensions invoices created through Transaction Broker

The current Access Dimensions invoices integration uses a lot of information from the Order record in Dimensions, to link through to the product details, and get the line details of the original order.

If Invoices are created via Transaction Broker, there is no corresponding Order record, so the Invoice import(s) in Automation Manager cannot import them.

The Invoices import could be amended to look in the SL_TRANSACTIONS and SL_PL_NL_DETAIL tables in DImensions to get this information, and remove the requirement for an original Order record to exist.