Revert "Migrato anche backend"

This reverts commit d1b57a26dc1667e48308bd1cdfae0740c0cf8690.
Revert "Polimi Oauth separato"

This reverts commit 5ae7ccda9cb68d73a8715c9882a9327e8b58beed.
Provider caricato solo dentro third_party_auth
Merge branch 'polimi-oauth' of github.com:marcore/edx-platform into polimi-oauth