Shake app icon when new window can't be opened

[danirabbit]

Problem

Currently we do a Gdk.Beep when a new window can't be opened in response to a middle click, but there's no visual feedback that the action was rejected

Proposal

We should do a little shake in addition to the beep to make sure there's visual feedback that the task can't be completed

Prior Art (Optional)

We use a shake in other places like the Lock screen and Polkit dialog to indicate input was rejected

[teamcons]

I will try something :)