feature: enable running of external tests outside of containers

[judovana]

it may be great if external tests can be run out of container, directly on host.

It must not be a goal of this proposal to change default runs. Those should remain isolated in container.

It should not be the goal oft his proposal install all dependencies of those tests to target host. Those tests ahve huge, and weird depndencies, which may be impossible to automate properly across distributions, and they can by accident polute the unaware host.

[smlambert]

Will close as duplicate of #2026