Support for localized non-latin languages

[HadrienGardeur]

With the new approach to localization, I'm now able to add new languages much faster than before which will allow me to easily extend this project to 20+ langues.

That said, I'm quite worried about support for non-latin languages on Apple devices. Based on some early testing, in addition to localizing the usual strings (quality, language and regions) there are also voices where the name itself is localized and doesn't use latin characters.

I've tried Greek for example and only one of the two voices available has a non-latin representation in the settings of the OS. To deal with that problem, we would either need to include a new property or recycle one of the existing ones. altNames combined with localizedName could be a good fit for that, since the values currently documented in the localization PR are redundant with information that can be generated/inferred.

I don't see myself revisiting all voices for all languages though, so I would only consider doing this work on variations for relevant languages.

This will need further exploration before taking any decision, but I'm opening this up to discussion in the meantime.