Allow users to see billing receipts in the dashboard

[travjenkins]

Some users would like to see receipts on the billing page. They want to specifically see a receipt and not just the invoices we already provide.

Would prefer that this is opened within the dashboard and not just linking over to Stripe.

[travjenkins]

Stripe mainly supports receipts through emails and opening a link to their site.
https://docs.stripe.com/receipts

They do have an API that provides receipts for users
https://docs.stripe.com/api/charges/object#charge_object-payment_method_details-card_present-receipt

We might be able to offer PDF download of the receipt (like we do with invoices). Or we could allow users to ask for an email when something is paid?

[travjenkins]

It would also be great to email the user this after the invoice has been paid.