Dragging windows allows cursor to become detached from original location

[guusw]

I recently upgrade our project from 0.25 to 0.27 and noticed the dragging of windows now allows the mouse to be detached from the window being dragged, which I don't think is desirable as it results in awkward dragging.

I noticed that this is not unique to windows or our project, as you can easily replicate it in the web version (egui.rs) as well by just dragging windows into the side bars

Left: 0.25.0 -- right: 0.27.2

drag-egui.mp4