Emit paymentMethodRequestable event after 3DS Challenge is completed

[jplukarski]

Summary

Jira

Holds off sending the paymentMethodRequestable event until after verifyCard has completed for 3DS flows.

Addresses #805

Testing strategy:

Run the Drop-in demo in development mode and add the following query parameters to the URL in your browser:

?threeDSecure=true&authorization=<generate-a-client-token>

Then test each test card listed in our 3DS documentation to make sure everything works as expected on each flow. Open the dev console and notice that the event does not fire off until 3DS authentication is completed:

paymentMethodRequestable {paymentMethodIsSelected: true, type: 'CreditCard'}

Checklist

• Added a changelog entry

Authors

List GitHub usernames for everyone who contributed to this pull request.

• @jplukarski

[hollabaq86]

This is a good first pass, but I don't think we cover all scenarios where 3DS "completes."

Why does 3DS have to be so complicated :lolsob:

[jaxdesmarais]

🚀

[hollabaq86]