Name collisions

The following discussion from !3 (merged) should be addressed:

• @alossent started a discussion: (+1 comment)

  What if a project exists, but is something else entirely? (e.g. name collision with a paas-infra-* project)

  In this case we should not touch the existing project if it is not managed by this operator!

  Consider using a label to distinguish projects managed by this operators from other projects.