Add option to the container script to transparently route traffic through tor

We could have an option in the container script to transparently route traffic through Tor.

In tor-browser-build this would allow us to use mmdebstrap and install packages using tor (as an option).

To do that, we can reuse the work done in https://gitlab.torproject.org/boklm/torsocks-netns (probably with the redsocks mode).