T6594, Logged out users should see "View Raw" in dropdown of timeline items

Summary: Fixes T6594, Logged out users should be able to "View Raw" comments in public objects.

Test Plan: Log out, open maniphest task with comments, open dropdown associated with comment, click "View Raw", should be able to see raw comment.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Maniphest Tasks: T6594

Differential Revision: https://secure.phabricator.com/D11295