(stable) Restrict watching and member project display better

Summary: Fixes T12713. We don't need to show watching and member info on other views other than ApplicationSearch (for now) so add a few methods to restrict the calls.

Test Plan: Visit project search, profile, project home, project home with subprojects

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T12713

Differential Revision: https://secure.phabricator.com/D17883