[FEATURE] conditional Authorization header passthrough to upstream service

[xmlking]

I would like to have the following feature. If it is already supported with some configuration, please advise.

• If the client request comes with Authorization: Bearer <external-jwt-token>, this middleware should just verify the signature and if it is good, passthrough Authorization: Bearer <external-jwt-token> to the upstream service.

• If the client request does not have Authorization: Bearer <external-jwt-token>, then redirect the user to the configured OAuth provider and extract the claims, then create a new small JWT, then forward Authorization: Bearer <internal-jwt-token> to the upstream service.