Implementing Spaces in Countdown

Summary: Implements T8734

Test Plan: Verify that countdowns can have spaces associated with them. Verify that non-default spaces are displayed in the header of the countdowns in the result of the query.

Reviewers: lpriestley, epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D13634