"Resolve" reports in Admin/Moderation

In Admin->Moderation (/admin/reports) I see a bunch of reports. I open one and I see that the object of report has been already deleted. I think in such case the report should be taken down from the list or grayed out - the latter idea so admin team don’t loose history
Or maybe the list should be split in two, like registration does?

Also, I would like to be able to mark reports “resolved” - hidden or grayed out just for me, so I know I already decided that report is not for me. For WebUI maybe store the list of “resolved” reports in browsers’ store, so it doesn’t pump up the db?