Currently users are taken out of the app to complete the users donation flow. This creates the following negative experiences:
* slower experience from needing to switch apps
* thankyou.wikipedia.org attempts to use native view
* user looses reading location
The goal here is to leverage in-app webviews to improve this, as well prep us for having a more unified experience for native amount selection and payment selection within the apps.
banner (native view) --> `donate.wikimedia.org` (app web view) --> `payments.wikimedia.org` (app web view) --> `thankyou.wikipedia.org` (app web view) --> continue reading
Requirements for both apps:
* support autofill for address and credit card credentials
* Flow can be entered via banners AND other entry points such as from the apps menu
* This flow can be A/B tested against the existing flow.