Summary:
This commit adds a couple of missing assets, including the icon for the
plugin list and other misc icons. It also switches to the new UI where
we use the thread timestamps to display the reminder date in the
Reminders perspective instead of using mail labels. It also adds a
header to the threads inside the reminders perspective to indicate that
a reminder will be triggered if no one replies to their email.
It also adds a header to indicate when a message has been brought back
to the inbox due to a reminder based on sdw's designs.
Finally it restores some code that magically disappeared when landing
reminders + other misc cleanup
Test Plan: Manual
Reviewers: bengotow, halla
Reviewed By: bengotow, halla
Differential Revision: https://phab.nylas.com/D3388
