Replaced inactive plugin messages filter.

With an inactive plugins filter.
Fixed uncalculated CRCs displayed in editor.
Fixed checkbox menu item clicks.

The checkbox was restricted to the middle of the item, so edge clicks
wouldn't hit it.
Removed dead CSS override.
Implemented conflicts filter.

However, I've noticed that the checkbox never actually changes state,
despite the `changed` event, so the checkbox always `checked` as true.
Fixed card highlighting.

Also made last <content> selector more general in plugin card.