fix(340): catch Stripe Payment error and save error message

[machikoyasuda]

Resolves #340
Impact: major
Type: feature

Issue

• Issue: A customer does not know if a payment failed, and is stuck at the page when errors occur.
• Feature: After a customer saves an invalid credit card and clicks Check Out, the customer should be taken back to the Cart page on Step 3, Payment, and an InlineAlert should appear with the error message.

Solution

• - Catch Stripe payment error message
• - Pass an alert object to CheckoutActions:
• - Add InlineAlert to app
• - Take user back to Step 3 and display InlineAlert
• - Reset the payment form

Testing

1. Test these Stripe cards pre-configured with errors: https://stripe.com/docs/testing#cards-responses

[nnnnat]

💯 Looks good! There are a few undefined required prop warnings after checkout completes but that will need to be addressed in the component library.