Notify when unauthorized client connects.

[vincentparrett]

Currently there doesn't seem to be any way of notifying the HalibutRuntime consumer when an unauthorized users attempts to connect (other than a debug log message).

I think it might be useful for some applications to make the users or admins aware of these attempts. Looking at the code, it doesn't look too difficult to add a callback from the SecureListener and SecureWebSocketListener's Authorize method.

PR on the way.

[vincentparrett]

Implemented.