Support layout --root

[nikitabobko]

Discussed in #939

^{Originally posted by yngvedh January 8, 2025}
I'm using a setup where I have two vertical accordions side by side so that I can manage my windows into two groups, left and right. I have a laptop monitor (A) together with an extrawide external monitor (B).

On A, I want the two accordions in a horizontal accordion because it is not wide enough to have the windows side by side. On B I want them tiled because it has enough room.

Now when I move a workspace from one monitor to the other, I also want to switch the layout of the root node.
I haven't figured out a way to do this so I'm forced to reset the layout and set it up again which is quite a hassle.

The ability to toggle the layout of the root node would solve this for me.
Something like this would do the trick: aerospace layout --root tiles accordion

Alternatively aerospace could automatically collapse tiles to accordions when becoming too narrow. Optionally, of course.