Add support for Central Asian Turkic language characters to Noto Nastaliq Urdu

[tiroj]

Given the broadly Persianate of the Turkic linguistic cultures of Central Asia that have historically used—and in some countries still use—Arabic script, it is appropriate to use nastaliq style fonts for these languages, but so far I have been unable to find any nastaliq font that supports all the characters for all these languages. Noto Nastaliq Urdu supports several of the historical and current alphabets of some of these languages, but not all. While a specifically Persian style nastaliq would be ideal, extending Noto Nastaliq Urdu to support these characters would be a helpful first step.

I don’t have a complete and verified list of the missing characters that should be added, so am creating this issue as a place to log them. The following are ones I have identified so far:

KAZAKH
ٵ ٶ ٷ ۋ ٸ
ٴ
KYRGYZ
ۅ ﯗ ۉ ﯞ

[My immediate need regarded orthographies in the Soviet Republics immediately prior to the adoption of short-lived Latin script alphabets in the 1920s, so I have not yet looked closely at current use of Arabic script for these languages in Iran or other countries.]

[tiroj]

Note that Unicode discourages use of the Kazakh high-hamza digraph characters, and instead sequences of high-hamza (U+0674) followed by the base letter should be used (not base + high-hamza as the compatibility decompositions of the digraph characters suggest). Note also that the high-hamza should be a full size hamza, not a small diacritic form, but raised off the baseline. The Amiri font provides a good model for scale and height of the high-hamza (although I would kern more closely to the base letter).

[sal-ammoniac]

And,the arabic orthographies of Kazakh and Kyrgyz are still used in China.