Allow user to use multiple expense class from same fund on one invoice line or POL

Purpose: In order to use expense classes the user will need to be able to selected them when adding Fund distribution(s) to orders and invoices. User will in some cases need to pay an invoice against two different expense classes from the same fund

User story statement(s):

As an acquisitions invoicing user
I want to be able to pay an invoice line or encumber a POL against two expense classes from the same fund
so that when I order something that is both "Electronic and Physical" I can split the cost between two expense classes but all the money will come out of one Fund Eg. HIST

Scenarios:

1. Scenario:
   • Given the user has added a Fund distribution
   • When the fund selected has expense classes
   • Then I can add it twice and select two different expense classes
2. Scenario:
   • Given the user has added a Fund distribution
   • When the same fund is added twice but different expense classes are selected
   • Then user can assign amounts to both without the multiple funds validation error appearing (You can not have multiple distributions for the same fund.)
3. Scenario:
   • Given the user has added a Fund distribution
   • When the same fund is added twice with the same expense classes selected
   • Then user is shown validation error message ("You can not have multiple distributions for the same fund with the same expense class.")