Button to mark all "merged" items as done in notifications. #3969

Hello, could we have a button in the notifications page that automatically marks all merged items as done? Currently I'm having to click on each item, then mark as read. It's fine if the whole project has all items merged, as there's a Mark as done button, but e.g. when there's one or two not merged, I'd like to make sure they stay in my notifications.