Policy - update TODO to better tracking task for Maniphest drag and drop policy fix

Summary: Ref T7094. This is a bit involved and should be tackled as a separate effort. The good news is policy still saves the day here but (back to the bad news) its a bad user experience.

Test Plan: NA, just a comment

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7094

Differential Revision: https://secure.phabricator.com/D11658