localedata: Fix several issues with the set of characters considered 0-width [BZ...

localedata: Fix several issues with the set of characters considered 0-width [BZ #31370]

= `Default_Ignorable_Code_Point`s should have width 0 =

Unicode specifies (https://www.unicode.org/faq/unsup_char.html#3) that characters
with the `Default_Ignorable_Code_Point` property

> should be rendered as completely invisible (and non advancing, i.e. “zero width”),
if not explicitly supported in rendering.

Hence, `wcwidth()` should give them all a width of 0, with two exceptions:

- the soft hyphen (U+00AD SOFT HYPHEN) is assigned width 1 by longstanding precedent
- U+115F HANGUL CHOSEONG FILLER needs a carveout
  due to the unique behavior of the conjoining Korean jamo characters.
  One composed Hangul "syllable block" like 퓛
  is made up of two to three individual component characters, or "jamo".
  These are all assigned an `East_Asian_Width` of `Wide`
  by Unicode, which would normally mean they would all be assigned
  width 2 by glibc; a combination of (leading choseong jamo) +
  (medial jungseong jamo) + (trailing jongseong jamo) would then have width 2 + 2 + 2 = 6.
  However, glibc (and other wcwidth implementations) special-cases jungseong and jongseong,
  assigning them all width 0,
  to ensure that the complete block has width 2 + 0 + 0 = 2 as it should.
  U+115F is meant for use in syllable blocks
  that are intentionally missing a leading jamo;
  it must be assigned a width of 2 even though it has no visible display
  to ensure that the complete block has width 2.

However, `wcwidth()` currently (before this patch)
incorrectly assigns non-zero width to
U+3164 HANGUL FILLER and U+FFA0 HALFWIDTH HANGUL FILLER;
this commit fixes that.

Unicode spec references:
- Hangul:  §3.12 https://www.unicode.org/versions/Unicode15.0.0/ch03.pdf#G24646 and
  §18.6 https://www.unicode.org/versions/Unicode15.0.0/ch18.pdf#G31028
- `Default_Ignorable_Code_Point`: §5.21 https://www.unicode.org/versions/Unicode15.0.0/ch05.pdf#G40095.

= Non-`Default_Ignorable_Code_Point` format controls should be visible =

The Unicode Standard, §5.21 - Characters Ignored for Display
(https://www.unicode.org/versions/Unicode15.0.0/ch05.pdf#G40095)
says the following:

> A small number of format characters (General_Category = Cf )
> are also not given the Default_Ignorable_Code_Point property.
> This may surprise implementers, who often assume
> that all format characters are generally ignored in fallback display.
> The exact list of these exceptional format characters
> can be found in the Unicode Character Database.
> There are, however, three important sets of such format characters to note:
>
> - prepended concatenation marks
> - interlinear annotation characters
> - Egyptian hieroglyph format controls
>
> The prepended concatenation marks always have a visible display.
> See “Prepended Concatenation Marks” in [*Section 23.2, Layout Controls*](https://www.unicode.org/versions/Unicode15.1.0/ch23.pdf#M9.35858.HeadingBreak.132.Layout.Controls)
> for more discussion of the use and display of these signs.
>
> The other two notable sets of format characters that exceptionally are not ignored
> in fallback display consist of the interlinear annotation characters,
> U+FFF9 INTERLINEAR ANNOTATION ANCHOR through
> U+FFFB INTERLINEAR ANNOTATION TERMINATOR,
> and the Egyptian hieroglyph format controls,
> U+13430 EGYPTIAN HIEROGLYPH VERTICAL JOINER through
> U+1343F EGYPTIAN HIEROGLYPH END WALLED ENCLOSURE.
> These characters should have a visible glyph display for fallback rendering,
> because if they are not displayed,
> it is too easy to misread the resulting displayed text.
> See “Annotation Characters” in [*Section 23.8, Specials*](https://www.unicode.org/versions/Unicode15.1.0/ch23.pdf#M9.21335.Heading.133.Specials),
> as well as [*Section 11.4, Egyptian Hieroglyphs*](https://www.unicode.org/versions/Unicode15.1.0/ch11.pdf#M9.73291.Heading.1418.Egyptian.Hieroglyphs)
> for more discussion of the use and display of these characters.

glibc currently correctly assigns non-zero width to the prepended concatenation marks,
but it incorrectly gives zero width to the interlinear annotation characters
(which a generic terminal cannot interpret)
and the Egyptian hieroglyph format controls
(which are not widely supported in rendering implementations at present).
This commit fixes both these issues as well.

= Derive Hangul syllable type from Unicode data =

Previosuly, the jungseong and jongseong jamo ranges
were hard-coded into the script. With this commit, they are instead parsed
from the HangulSyllableType.txt data file published by Unicode.
This does not affect the end result.

Signed-off-by: Jules Bertholet <julesbertholet@quoi.xyz>