Address window placing problem on rotation

When changing the workspace size, clients will need to reposition themselves. This leaves a short amount of time where strutted clients (e.g. panels) will be floating in the wrong place.

This change makes it so when the area could not be properly calculated, we ignore these clients until they start giving us proper values again.

This is a bit of a workaround though, it would make sense to implement client placement more synchronously so we didn't have weird moments where everything is wrong.

It's mostly prominent on the phone but it happens elsewhere when you rotate.