Allow named queries to be reordered by dragging

Summary:
Also you have to drop them. So drag, and then drop.

This needs some cleanup and reconciliation/generalization with the Maniphest implementation. In particular, you can't drag things to the very top right now, and they should share more CSS and more behaviors.

Test Plan:
Look I alphabetized them:

{F45286}

Reviewers: chad

Reviewed By: chad

CC: aran

Differential Revision: https://secure.phabricator.com/D6136