Now xfs is working, `prepare_host.yaml` is modified to add `xfs` to
the list of modules loaded at each boot.

If module is added to that list, than is also loaded with a modprobe
handler.

If xfs is not working with `role/lxc_guest`, run the patched
`prepare_host.yaml` againg.

- New apt multipackage style

- Tabulation in `templates/interfaces.j2` and in `/etc/lvm/lvm.conf`
  line fixed: in Debian buster tabulation is used to indent this config
  files by default.

`python3` and `python3-lxc` are installed with apt instead of `python`
and `python-lxc`.

This commit includes the configuration of vlans on the host
for virtual machines. By configuring a bridge on the br0 interface
we can host the virtual machine vlan and by setting a vlan on the
logical device we can include it into the management vlan.
All variables are included from playbook