R1:78438951c804

Refactoring to use `PHUICalendarListView` instead of boxes

Summary: Ref T4393, Refactoring to use `PHUICalendarListView` instead of boxes

Test Plan: See new sidebar

Reviewers: chad, #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T4393

Differential Revision: https://secure.phabricator.com/D12743