Now that the blue dot for mark as read/unread is in the corner of every notification, it's redundant in the dotdotdot menu.
In the vast majority of notifications, mark as unread is currently the only function in the dotdotdot menu. So removing it enables us to remove a lot of clutter. Just to spell out the details with regard to that:
- In the very few cases where there are items in the dotdotdot menu aside from mark as unread/read, the menu should still display.
- In all other cases (where mark as read/unread is the only option), the menu should no longer display.
- Ideally, we'll construct this menu so that if we add new options to a given notification type -- I'm thinking of a secondary link beyond the two currently allowed in the main message display -- those options will automatically cause the menu to display. (Or maybe that already works -- see T125949)