* Add notification dots to thread summary icons
Adopts new IndicatorIcon from compound to have threads icons with
indicator dot (that aren't also buttons). Adds green & red dots on
the threads icon in the thread summary to indicate notifications.
Changes the notification level dots colours in the threads panel to
be green to match.
* Update test for new CSS class
* Update snapshots with new class name
* Another snapshot update for new class name
* Replace more uses of old class name in tests
* More snapshot updates for new class name
* Unsure how this ever worked in chronological mode
* More snapshot updates
* Fix dot colours
* Upgrade to compound-web 3
* Fix computed notification levels
* Add test for notificationLevelToIndicator
