R1:1329b7b51ef8

Add password authentication and registration to new registration

Summary:
Ref T1536. Ref T1930. Code is not reachable.

This provides password authentication and registration on the new provider/adapter framework.

I sort of cheated a little bit and don't really route any password logic through the adapter (instead, this provider uses an empty adapter and just sets the type/domain on it). I think the right way to do this //conceptually// is to treat username/passwords as an external black box which the…