Partial refunds - Donation integration (SFDC/Basket/Stripe/Paypal)

[desiree-mofo]

We need to account for the use case where partial refunds are granted. The entire record is being marked as Closed Lost in SFDC, which is incorrect. In this case (Strip Txn ID: ch_1BVjIYG8Mmx3htnxbKxopb5V ) the donation was set up for $25, but the user requested a refund of $20 for a net donation of $5. That should be reflected in the system.

@stephaniemcv - we should outline what this needs to look like in SFDC in terms of data structure and provide those details to @cadecairos and @pmac