Remove dependency on SimpleSAMLphp Auth

The authManager is a service pulled from SimpleSAMLphp Auth. All the calls to it are things we can do in a local Authentication Manager service that isn't tied to SimpleSAMLphp. The whole of the auth manager doesn't need to be cloned, and we may be able to get away with a few internal helper functions in RedirectAnonymousSubscriber.

Module functions without loading SimpleSAMLphp.