Pass controller request object to idp settings adapter

[tedkeep]

In applications where the domain name can change, the use of the ActionController request object is required so the SP url can be set dynamically.

This change makes it so the request object can optionally be passed to the IdPSettingsAdapter#settings method so urls can be created dynamically.

[adamstegman]

Thanks for this addition! Now I wish we'd used a hash instead of positional arguments 🙂