FLOATING: prevent random window resize whilst dragging across displays

In yabai, when we have a floating window, and we want to drag it between displays; since we are required to disable "Displays Have Separate Spaces" option in system settings, it means when we drag a window across the display to another, it can change the size of the window. It would be preferable to maintain the same window size while the window is being dragged across displays in floating mode.

No source file, test, or entry point is identified in the issue. First reproduce the resize while dragging a floating window between displays with Displays Have Separate Spaces disabled, then trace the display-transition handling. Done means the floating window keeps its original size throughout the drag; add or update coverage if the project has a relevant test location.

Written by the indexing model from the issue text.