Handle auth on tsm decoupling layer side

In general we don't want to make the datastream information available for everyone, so we need some kind of authentification and authorization.

The idea was to reuse the access token that we got from the IDP in the sensor management system. That way it is relativly easy to work from the sms frontend with the tsm dl implementations and still it is possible to make very fine granular decisions about who can see what.