shift_widgets_up not working, also add shift_widgets_left

[cantak]

I added a shift_widgets_left property and all corresponding methods mimicking the shift_widgets_up that was already there. Worked fine. Then I ran into a bug which I found also exists in shift_widgets_up. Happy to share the new feature I added but trying to fix this issue first. I can reproduce even if I revert my changes out.

Drag a widget on top of another one where the one you hover over gets shifted down. It will get a lot of space between it and the one you were dragging. Let go. The one you dragged will shift up as expected but the one that auto-moved will not. It will stay where it is. Drag it 1 pixel and it will correct itself. Need it to correct itself once the dragging stops.