Reorganize VCAPI menu structure

Currently, VCAPI is still using the old, old menu structure jpetso set up - everything lives under admin/project. This is OBVIOUSLY not optimal, but it's only occurring to me that we really need to change it now that I need to add new menus for #990644: Improve backend interaction with views.

I think a better approach would be to move repository management under admin/content (they are, after all, entities), and then move any meta-configuration into a new area under admin/settings.