origin-manager: rework devel-project.py as osc-origin subcommand

[jberry-suse]

Since devel project concept is a subset of origin concept which is already able to wrap Factory all the features provided by devel-project.py could be ported to be based on origin instead of devel directly. This would allow the tool to be used for Leap and SLE to provide overview their upstreams (origins). Could also utilize the cross-OBS instance code for request queries to handle the openSUSE.org IBS remote the same way origin manager does.