add Twint payment method

[joelherzog]

https://docs.stripe.com/payments/twint/accept-a-payment?platform=web&ui=stripe-hosted

[joelherzog]

In this PR I added Twint as a payment method option. Twint was added to Stripe a few weeks ago and is a very popular payment method in Switzerland. Stripe Twint Docs

I have gone through the whole repo and from my understanding of the plugin is should be enough to add the new option like this (not sure if there is something going on the background as well as I couldn't find the payment method specific "confirm payment" handler). Let me know if this is ok like this.

And sorry for just opening a PR. I asked about Twint in the community forum but haven't received an answer yet and my deadline is coming up soon.. If you can't add the payment method in the coming week. Just let me know, I will then create a custom integration using the Stripe library via CDN as well as Supabase Edge functions etc..