Calendar event monograms, part 4. Typing E{id} makes the object available in global search.

Summary: Closes T7928, E{id} is available via global search.

Test Plan: Create calendar event, search for its monogram in global search, event should be accessible.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7928

Differential Revision: https://secure.phabricator.com/D12581