Visually represent blocked CDN-requests

[aereaux]

Right now this extension displays the number of and details about the requests that were rerouted locally, but it does not do the same for requests that were cancelled (with the "Block requests for missing resources" setting enabled). Right now (as far as I can tell) it just silently drops them. It would be nice if it provided some notification, and it would be especially helpful for debugging. It would be even more helpful if it were possible to selectively enable or disable certain resources from the menu, but that is a separate feature request.

[EC-O-DE]

I have uMatrix and it shows when blocked, but not history. I'm not sure how handy history information would be.