Query for recurring event parents should accept a "not a child of anything" clause
Summary: Closes T8371, Query for recurring event parents should accept a "not a child of anything" clause
Test Plan: querying for a list of events with recurring events should still work the same.
Reviewers: epriestley, #blessed_reviewers
Reviewed By: epriestley, #blessed_reviewers
Subscribers: Korvin, epriestley
Maniphest Tasks: T8371
Differential Revision: https://secure.phabricator.com/D13140