Updates UCD to Unicode 16.0 (released 2024 Sept).
Previously: 0fdffc18, #7502, #14680
Unicode 16 adds several new character sets and case folding rules.
However, the existing ucgendat script can still parse them.
This also adds a couple test cases to make sure the new rules for
East Asian Wide characters and case folding work correctly. These
tests fail on Unicode 15.1 and older because those verisons do not
contain those rules.
Updates UCD to Unicode 15.1 (released 2023 Sept). The upcoming
Unicode 16 version will be released roughly on 2024 Sept.
Previously: 0fdffc18, #7502
UCD 15.1 `DerivedNormalizationProps` contains multiple properties in
the same line, which breaks the parser. This also updates the
`ucgendat.php` script to allow 2 or three fields in each line, and to
look for the `Cased` and `Case_Ignorable` properties in either of the
fields to mimic the previous behavior.