ENT-447 Add ability to hide auth warnings for enterprise context.

When a user comes in through an sso provider and arrives at the login
or registration page, there is a warning message that comes up to indicate
that the user has to take an action to sign in and register and thus
link their sso account to their edx account. However, it is confusing,
particularly for the enterpise context. This diff disables these messages
from being rendered if these pages are being shown in an enterprise context.

lms/djangoapps/student_account/views.py

@@ -220,6 +220,7 @@ def update_context_for_enterprise(request, context):
         )
         context.update(sidebar_context)
         context['enable_enterprise_sidebar'] = True
+        context['data']['hide_auth_warnings'] = True
     else:
         context['enable_enterprise_sidebar'] = False