[LyX/master] missing background in xetex and fix RTL stuff in preview

[Udicoudco]

On Sun, Jun 9, 2024 at 1:55 PM Udi-Fogiel <udifoglle at gmail.com> wrote:
>
> commit 64aad586f49b9047082356e5f217fc6147ac9500
> Author: Udi-Fogiel <udifoglle at gmail.com>
> Date:   Sun Jun 9 13:36:35 2024 +0300
>
>     missing background in xetex and fix RTL stuff in preview
>
>     * previwes with xetex did not produce any background (\pagecolor does not work for some reason), adding the direct command for that, \special{background <color>} inside the preview box solved it.
>
>     * similar to #12923 we should push the color node in horizontal mode
>
>     * there is a bug in preview with LuaTeX with main RTL language, this commit fix this bug, but it should be removed when it is fixed upstream (the code related to \pr at set@pagerightoffset)

Riki, is this ok for stable?