Render the Amazon Pay button in the editor

[alexflorisca]

Currently, a preview image of the Amazon Pay button is being rendered in the editor. With new changes about to be introduced in Core, we are asking payment extensions to render the actual buttons in the editor instead of a preview. This has several benefits:

• It gives the merchant a more accurate representation of what the shopper would see on the front end of a store
• It provides feedback to the merchant as to which express payment buttons support the new height and border radius controls

This will involve:

• loading the SDK or client side scripts which load the button in the editor
• When calling registerExpressPaymentMethod, passing the same component to the edit property as the content property.