Add support for rotating panes around in the window, without changing the layout

In tmux it's possible to move/swap opened panes in different ways.

Moving panes around in tmux:

C-a C-o        rotate window ‘up’ (i.e. move all panes)
C-a M-o        rotate window ‘down’

https://man7.org/linux/man-pages/man1/tmux.1.html:

     rotate-window [-DUZ] [-t target-window]
                   (alias: rotatew)
             Rotate the positions of the panes within a window, either
             upward (numerically lower) with -U or downward (numerically
             higher).  -Z keeps the window zoomed if it was zoomed.

From @kostrse in #4922