Parameterize search in Pholio

Summary:
Ref T4100. Ref T5595.

• Add project query + edgelogic support.
• Support user selector functions.

Test Plan:

• Used search to find stuff.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T5595, T4100

Differential Revision: https://secure.phabricator.com/D12531