Calendar event detail page should show host.

Summary: Ref T8027, Calendar event deatil page should show host.

Test Plan: Open calendar event, property list should include the host.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Maniphest Tasks: T8027

Differential Revision: https://secure.phabricator.com/D12683