Removing a direct charge on invoice doesn't appear to remove it

[Tiffany Little]

Tested on 3.13 as part of the July AIG meeting.

Testing on the new acq invoice UI, if you add a direct charge and before saving the invoice try to remove said direct charge, the charge does not disappear and the Save button is disabled. We would expect that when the Remove button is clicked that the direct charge would disappear at that time.