AWS Route53 module for certbot DNS challenge

[JohnPreston]

Hello team,

Loving Stalwart, incredible work and looking forward to using it for the long-run.
It'd be amazing please to support Route53 for the DNS challenge.

Either the admin

• Provides an access/secret key in the UI, which gets stored into the config/DB and used to make API calls
• Leaves the fields empty and the service uses the default chain provider credentials as per most (if not all) the AWS SDKs

Not asking for DNS entries management for the domain or anything like that, that's purely up to the admins to know what to set into the DNS records.

Thank you so very much.