[WIP] [DO_NOT_MERGE]: introducing osc (end-user CLI)

The main idea around this was to concentrate the dependency of the command line library (Cobra now) in only one place, base/base.go. But I agree it adds an extra layer of complexity we don't need (i.e. I will run into trouble when start using flags), so I was already planning to get rid of this idea - I'll refactor.