Use study status properly

This blocks the attachment of raw data to the study until after the study metadata is approved. It also adds two buttons for admins to approve a study and to make a study public.

This finishes #476 
Thanks. Agree that it should not go in this PR as there are at least two other devs that I know of who are working on code within this same function. But refactor on this should be something that happens before too long for sanity sake