BiDirectional text support

[XVilka]

In the modern world, the support for some languages that are right-to-left and mixing them with left-to-write words and numbers is crucial for a different software. At some point, this should be supported everywhere, including the console.

I started to gather the information about BiDi support in various console terminals (and programs) in analogy with true color crusade at https://gist.github.com/XVilka/a0e49e1c65370ba11c17

New console BiDi specification was recently implemented in libvte by @egmontkob: https://terminal-wg.pages.freedesktop.org/bidi/implementations.html#vte

Note, that with the release of GNOME 3.34 the support of BiDi is available in Gnome Terminal out of the box, which makes testing/implementing it in the other programs, such as dvtm way easier.