This moves the container-based code location and venvs.
The goal here is that the paths of Tower source for isolated
vs normal nodes matches (both in prod and local development) so that we
don't have to add a bunch of additional bwrap argument logic for
<location-of-isolated-tower-venv>.
instead of launching isolated tasks via `systemctl`, treat
`awx.main.isolated.run` as an executable that knows how to daemonize
additionally, add `setup.py isolated_build` for isolated Tower source
distribution
