RFC 8707 support

[jjg-123]

We do not list RFC 8707 (https://www.rfc-editor.org/rfc/rfc8707.pdf) as supported, however, we do accept the resource parameter in the authorization and access token phase and the gist of the RFC is that the server should accept it formally, then have some policy to do something with it.

Basically, we do that already. The task at hand therefore is to go through the RFC carefully and make sure we actually are compliant, then list it as a supported spec.