Don't install pmdc to sbin by default, but declare that in the binary packaging

This MR removes the [install]/install_scripts options from setup.cfg - this operates globally when present so messes with python3 -m venv/virtualenv as well just installing pmdc. The workaround is to remove the options altogether, but to make sure that the Debian/RHEL packaging includes it manually, so that those packages still see the script in /usr/sbin.