sync up bindings/python/nrm/setup.py with src/python/nrm-setup

[perarnau]

We should have one canonical implementation of how to launch our binary and wait for them to be ready.

nrm-setup started as a quick fix, but is valuable to users, so we should clean it up and make it available in the release. Most of its
logic can be moved to the Setup context we created in python, which should help.