feat(next): Add enabled and onError hooks to paypal component

[david1alvarez]

Because

• The current paypal checkout flow does not have a way to mark the cart as failed for errors on paypal's side that happen before the subscription is created.
• The current paypal element can be interacted at times when the form should be disabled

This pull request

• Adds bindings to the paypal disabled attribute, using their default element styling and protections when the element should be disabled
• Adds an onError hook to finalize the cart with error, and to reroute the user to the error page.

Issue that this pull request solves

Closes: FXA-7587

Checklist

Put an x in the boxes that apply

• My commit is GPG signed.
• If applicable, I have modified or added tests which pass locally.
• I have added necessary documentation (if appropriate).
• I have verified that my changes render correctly in RTL (if appropriate).

Screenshots (Optional)

Other information (Optional)

I am not able to verify the onError callback works yet, as I am waiting for access to the paypal sandbox instance, and the testing dashboard. If anyone else wants to verify this works in the meantime, that would be great!

[StaberindeZA]

nit. Could this use async/await syntax instead? https://mozilla.github.io/ecosystem-platform/reference/style-guides/node-style-guide#asyncawait

[StaberindeZA]

r+. ty for the change