This commit adds several improvements, updates and fixes to Unicode related logic.
- Update Unicode tables to version 16.
- Escaped strings now escape valid Unicode code points to /Uhhhhhh and invalid code points to /xhh.
- Generally applies RzStrEscOptions way more consistently. The legacy escape is still used at some places though.
- Fix inconsistencies in Unicode decoders/encoders and checkers. They now either return 0 on an invalid decode or the number of bytes the code point requires.
- Add many unit tests for Unicode related logic.
- Add helpers to check code points.
Part 2/9. Likely won't build in between parts.
Co-authored-by: wargio <deroad@kumo.xn--q9jyb4c>
29e25fd895