feat: move-insert windows using keyboard and mouse

[jmmaranan]

Today, grabbing mouse and keyboard shortcuts swaps the windows.

• Move windows inside a con and swap when the next sibling is the last item.
• This also allows a window inside a con to move out and remove the con if it is the last window.
• Use <Super> + <Shift> + hjkl to move-insert windows.
• Use <Super> + <Ctrl> + hjkl to swap windows.