Enable forwarding of original authorization header to (remote) authorizer

[catper]

Is your feature request related to a problem? Please describe.

Authorization is typically done on the subject but there may be additional information in the access token that is needed for a decision to be made. At present, it doesn't seem possible to forward the original access token to a remote authorizer though, you can only forward data that exists within the authSession object can be passed on.

Describe the solution you'd like

I'd like the auth header to be forwarded to the remote authorizer.

[aeneasr]

Thank you! This makes definite sense and will be part of #441 once we work on it :)

[catper]

While waiting for #441 to happen, would it be acceptable to implement this as "stand alone" feature? I'm thinking all that's needed is a single line, copying the auth header and then we'd be done?

[ashneverdawn]

I'm interested in this too.

[aeneasr]

Yes, sounds good! Open to contributions! :)