Not by a mix of host task type (CI server or not) and whether or not the
host is virtual or physical.
Also only differentiate on the duration not the rate, to not
accidentally exclude slow hard disks.
This groups the files and templates for each host together and therefore
makes it easier to see all the (config) files for a host.
Also clean up incorrect, unused docker_compose config for mumble and
clean up unused engelsystem configs.