Contain all the things

This PR removes anchors where not necessary and instead ensures classes will be included with `contain` without an explicit depedency chain. These dependecy are generally not need and should be only used if explicitly needed, e.g. if a service depends on a database being present before start.

Furthermore, there are no more references to devstack in the code. :panda_face: 
@fpletz any ideas how that can be improved?