Add read notification service

* Added service call for getting all notifications or only non-read ones
* Added in web call to mark something as read by passing in `username` and `notificationId`
Adding in the note that testNotificationServiceStatusUpdate() is not guaranteed to occur before testNewQueryForFiltertingOutRead().  Or is this something special with springboot's test that order is guaranteed?  Thoughts on adding in a 'save', then 'updateAsRead' to this test to help this test out?