Add functions used inside and outside of VMs

The helper functions in this library are for use by host-side scripts
(osbash) and by scripts running inside the node VMs.

Partial-Bug: 1312764
Implements: blueprint openstack-training-labs
Change-Id: Ie3f7ec480a70beea1abedb3bb81d7380b978d7b2
Merge "Add functions used inside and outside of VMs"