Allow users to search for signatures across documents
Summary:
Ref T3116. You can already search for sigatures on a specific document, but allow them to be searched across documents too.
In particular, this lets users answer questions like "Which of these 5 documents has alincoln signed?" / "Has alincoln signed all the stuff I care about?" / "who has signed either L5 or equivalent document L22?", etc.
Test Plan:
Reviewers: chad
Reviewed By: chad
Subscribers: epriestley
Maniphest Tasks: T3116
Differential Revision: https://secure.phabricator.com/D9770