Summary: Move all Intercom feedback code to a package. Change the appearance of the lower right question mark icon when a new intercom message is received (red, with repeating CSS bounce animation). New messages are detected by keeping the intercom window open (after the first time it's opened by the user), and listening for DOM mutations of particular classes.
Test Plan: manual
Reviewers: bengotow
Reviewed By: bengotow
Subscribers: evan
Differential Revision: https://phab.nylas.com/D2125