Make 'Record Payment' & 'Record Refund' visible regardless of whether the balance 'requires' one

Per #85

@JoeMurray agreed that it is OK to ALWAYS show 'record payment' & 'record refund' as opposed to currently it only shows 'add payment' if there it a balance to pay & add 'record refund' if there is a balance to refund. However, we need to be able to overpay & over refund - I'm going to work on this issue & seeing the UI afterwards (just having the links more often visible) might affect what people think 'makes sense'

I did start on this but discovered a regression when I started writing my preliminary test so it's on hold while that gets merged through to master