Allow to destroy existing hosted card field

[ravinderk]

As per requirement, we re-render smart buttons and hosted card fields when currency changes because PayPal SDK only processes currency which we pass in query param. The smart button can be destroyed by calling the close function but I did not find a similar function for hosted card fields.

GitHub Discussion: #44 (comment)

Can you suggest the best way to re-render the hosted card field without reloading the whole page?

[ravinderk]

I resolved this issue by preventing duplicate events on form submission.