This adds multiple consent modes to OpenID Connect clients. Specifically it allows configuration of a new consent mode called implicit which never asks for user consent.
Fix and issue that would prevent a correct ID Token from being generated for users who start off anonymous. This also avoids generating one in the first place for anonymous users.
This adjusts the CORS headers appropriately for OpenID Connect. This includes responding to OPTIONS requests appropriately. Currently this is only configured to operate when the Origin scheme is HTTPS; but can easily be expanded in the future to include additional Origins.