Display to users which payment methods are available before registration opens

[dunkOnIT]

In the case of Paypal, this is trivial.

In the case of Stripe, this is harder as payment methods are enabled on the organizer's profile. There may be a part of the Stripe API that exposes the payment methods an organizer has enabled, we can use this to display the payment methods to the user.

Intention: Allow users to be prepared with the payment method which is most advantageous to them before registration opens.