Add developer UI for accessing NUX and "Overheated" query states

Summary: Ref T11773. Not committed to this implementation, but adds some "Developer" query actions to jump to the nux/overheated states without needing to know secret magic URL variables.

Test Plan:

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T11773

Differential Revision: https://secure.phabricator.com/D16736