Add "View Options" dropdown to Differential / Audit

Summary:
Depends on D1921. Depends on D1899.

Add the "View Options" dropdown menu to Diffusion, with options like "show standalone", "show raw file", "show all", etc.

Test Plan: Viewed commits in Differential and Diffusion.

Reviewers: davidreuss, nh, btrahan

Reviewed By: btrahan

CC: aran, epriestley

Maniphest Tasks: T904

Differential Revision: https://secure.phabricator.com/D1932