R1:32d660c08f46

Added a `token_token` table in anticipation of some data-driven tokens

Summary: Ref T11217. This just adds the table that we'll store tokens in. It doesn't make use of the table at all yet. This is mostly pulled from this diff (D16178). Specifically I mostly followed Evan's instructions related to the token table here: D16178#189120.

Test Plan: I ran `./bin/storage upgrade` successfully and there were no schema errors.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley…