Tests moved from downstream plugin with minimal adjustments.
These tests require nmcli inside the server so advanced image
changed to rocky-9 cloud image. Other alternative, e.g. centos-9
does not have a default user and requires additional customization
for setting the user.
Additionally, moved utils.py and constants.py.
From config.py and base.py only relevant subset of code moved.
Change-Id: I6b538c13a15e94d072091b3218b2cd48ff20a70c
fa2d7457a8