Alert user when adding pol to invoice that has a different currency or vendor that the invoice

Purpose: Stop the user from creating inaccurate invoices

User story statement(s):

As a librarian creating an invoice,
I want to be alerted when adding a POL for a different vendor or currency that I've identified on my invoice
so that I am less likely to make mistakes in processing payments

Scenarios:

1. Scenario:
   • Given User is adding invoice line base on POL
   • When when clicking save
   • Then If POL references a different vendor or currency than invoice the user is asked to confirm they want to add it to the invoice
   • AND the message is as follows "You are adding one or more purchase order lines that are in a different currency than the one identified on this invoice. If you would still like to add these please click confirm. Note: The cost will be recorded in the currency idetified on the invoice."
   • OR "You are adding one or more purchase order lines that reference a different vendor than the one identified on this invoice. If you would still like to add these please click confirm. Note: The payments will be associated with the Vendor Identified on the invoice.