BREAKING CHANGE: bblayers.conf / bblayers.conf.sample of project
using CoreOS should be adapted to use external-layers instead
of layers for each moved layers
The layer.conf of meta-belden-coreos now depends on:
- meta-virtualization (needed for podman)
- meta-webserver (needed for cockpit)
The bblayers.conf.sample file now enable theses two layers and theirs dependancies