UI: Dragging UI windows prevents dragging the game window

[Nifim]

The UI windows seem to hold the mouse after being dragged. When playing in windowed mode, you cannot drag a UI window and then drag the FFXI window without first clicking outside of FFXI entirely.

Steps to Reproduce

1. Launch in windowed mode
2. Drag a UI window around
3. Click elsewhere inside FFXI
4. Attempt to drag the FFXI window itself - Fails
5. Click anywhere outside FFXI
6. Click back into FFXI, but not in a UI window
7. Attempt to drag the FFXI window itself - Works

Original Issue: https://github.com/Windower/windower/issues/295