Add support for Upper and Lower Sorbian, aka Wendish

[alerque]

Interesting feedback here typst/typst#3235 (comment) adding (lower) Sorbian and Croatian to the list, and confirming Czech and Slovak.

Sorbian is a minority language (< 50000 people), it doesn't have a 2-letter language codes. Unless mistaken the 3-letter codes are hsb (Upper Sorbian), dsb (Lower Sorbian) and wen (Sorbian or "Wendish" collectively)

Originally posted by @Omikhleia in #1963 (comment)

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While dealing with the explicit hyphen repetition handling I skipped Sorbian (which we now know can use that alternative code) because we don't have a language support file or hyphenation patterns for it at all. Since I'm guessing we can probably apply some other language's patters to it this shouldn't be too hard to add. Maybe after BCP-47?

[Omikhleia]

Since I'm guessing we can probably apply some other language's patters

You mean porting https://github.com/hyphenation/tex-hyphen/blob/master/hyph-utf8/tex/generic/hyph-utf8/patterns/tex/hyph-hsb.tex for Upper Sorbian, I assume.

[Omikhleia]

This would be an occasion to split hyph patterns from the segmenter in different files, add their origin details and the scripts that were used to build them into a Lua table -- so we could check they are up-to-date and have the tooling for re-generating them.