Improve Latin char normalization

This improves the normalization for Latin characters, mainly to address the concerns in #51 . This adds a very large number of new normalizations, especially in the 'Latin Extended Additional' block which for some reason was missing every capital letter.

I did not add normalizations in any new Unicode blocks, but I did slightly extend the 'Latin 1' block to also capture some of the subscripts; this is for consistency with the 'Subscripts and Superscripts' block which was previously handled. I also preserved the actual implementation of the normalize function in terms of the check order, etc. In particular, the generated code should be approximately the same. To verify this, I ran some crude benchmarks on a variety of input (all ASCII, sparse Unicode, heavy Unicode, all outside normalizatio ranges) and there was no observable difference, but definitely not super rigorous.

Finally, I inlined all of the char blocks, rather than replying on the 'sparse table' static generation which was implemented earlier. At least in my mind it is a bit easier to read in this form. It also makes it much clearer when characters are missed.

If someone knows more about proper transliteration, I would be happy if they could take a peek through the transformations; I only applied the transliteration in cases where I was confident and hopefully did not make any controversial normalizations.

Two questions for discussion:

Is chars::normalize a reasonable name? Maybe it would be more precise to call it chars::normalize_latin. But I guess this is quite an annoying breaking change. But the signature is the same so it would be easy enough to include an alias and mark it is #[deprecated].
Is committing to const fn reasonable?

helix-editor / nucleo

Improve Latin char normalization #60