window: Move all attached windows with parent

We'd break the loop for moving attached windows at the first window, meaning we'd only ever move a single attached dialogs or popup if it was the first window in the list. This doesn't work out well when there are multiple popups open, so don't break out of the loop at all until all windows are potentially moved.

This fixes an issue in gtk4 where one or more non-grabbing popups would end up unattached if there were more than one and the parent window was moved.