Fix quicksand interaction with HTTP GET prefilling in ApplicationSearch

Summary:
Fixes T10196. This is a weird interaction and this might not be the best long-term fix, but just get it working OK for now.

General problem is that Quicksand doesn't currently use GET for requests. This is a very unusual case where the method is relevant. In the future, I might change Quicksand to use GET.

Test Plan: Clicked "Open Tasks" with Quicksand active, got a results list.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10196

Differential Revision: https://secure.phabricator.com/D15082