Adding a calendar preview panel to people profile

Summary: Ref T9606

Test Plan: Open people profile for a user with events today/tomorrow, see a panel under badges panel with event list

Reviewers: chad, epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin

Maniphest Tasks: T9606

Differential Revision: https://secure.phabricator.com/D15851