postContributionAmountChanged(args)
args is a dictionary with the following keys:
view- The ActionTag form viewbaseAmount- Base contribution amount, before Cover Costs are appliedtotalAmount- Total contribution amount, after Cover Costs are appliedcoverCost- Cover Costs amount that is being applied to the base contribution amountcoverCostEnabled- boolean, true if cover costs checkbox is checked
This callback is called when the contribution amount for the form is changed.

