Add edge tables for Phlux

Summary: Fixes T13129. This at least makes the existing UI work again before we banish Phlux to the shadow realm.

Test Plan: Edited the visibility for a Phlux variable, didn't get an error. Nothing showed up in the edge tables when I made those changes, but at least it doesn't error out anymore.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, PHID-OPKG-gm6ozazyms6q6i22gyam

Maniphest Tasks: T13129

Differential Revision: https://secure.phabricator.com/D19387