We plan to use the "remind me later"-functionality of banners again this year. In order to make it work with the new skin, we need a template file for the confirmation page, that is shown after confirming the double opt-in from an e-mail.

Most of the functionality is happening in the banner and the donation application's backend and should work out-of-the-box:

• Entering e-mail-addresses in-banner (prototype)
• Sending an e-mail containing a link to confirm the subscription
• Processing the confirmation link clicks

Templates are missing from the cat17 skin - currently the respective route shows an error page

• Subscription_Form.html.twig (this is a prototype form that has never been used and probably never will be; if still present in 10h16, please remove)
• Confirm_Subscription.twig

The confirmation link in the email is broken (missing the server address):
/contact/confirm-subscription/<token>

Acceptance Criteria

• The template Confirm_Subscription is added to cat17.
• The content for it is taken from the skin 10h16.
• The confirmation link in the e-mail is fixed.