I've done some digging into whether we can mimic OR use display-buffer
when creating a new tab, and while we could do this, we also advertise
two other behaviors for tab-bar-new-tab-choice that would make the
function needlessly complex, as use/mimicry of display-buffer would only
help in the case of when tab-bar-new-tab-choice is t.

On a side-note (side-window? haha), I've got a patch that side-steps
(hehe) the issue of modifying the 'window-side parameter completely, by
binding to window--sides-inhibit-check to t.

Having bound this, the issues wrt split-window and delete-other-windows
is no longer present, and thus we no longer have to touch the
'window-side parameter at all.

The same can't be said for the 'window-atom parameter (there's no
variable to bind to ignore checks), so it still needs to be removed in
order to ensure a safe call to delete-other-windows and split-window.

Would this be a better patch? It's now less destructive on existing
window parameters.