Remove shield for Conduit API responses

Summary: 'cuz we don't need it and it's lame complexity for API clients of all kinds. Rip the band-aid off now.

Test Plan: used conduit console and verified no more shield. also did some JS stuff around the suite to verify I didn't kill JS

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T891

Differential Revision: https://secure.phabricator.com/D3265