"Mark as read" all sites under a tag

[timlod]

If Erik notices that something slipped past the differ that created a change in all links under a website (which should be in a tag), he may want to mark all those as checked at once.

dgtlmoon#317 may already implement this functionality, as I think it implements checkboxing, and then you could visit the bank's tab and mark them all at once. We'll have to see once it's on main.