Remove motivator panel

Summary: Removes the often funny, but never really used but will cause us bug reports someday.... cat facts.

Test Plan: Install cat facts, run storage upgrade, see no cat facts in menu.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T12126

Differential Revision: https://secure.phabricator.com/D17233