Checkmk Werk 12310: add cgroup v2 support for mk_docker.py

ID: 12310 Title: add cgroup v2 support for mk_docker.py Component: Checks & agents Level: 1 Class: New feature Version: 2.1.0i1 The output of the docker api differs depending on the cgroup version used on the docker host. checkmk can now handle the output of mk_docker.py running on a cgroup v2 host.