Improve kickoff's group for non-latin language.

Use icu transliterator to convert i18n'ed name into ascii for initial
character grouping. Since AppsModel does not use group(), just use group
to store this value for convenience.

Relevant qt feature request for having a new mode for section:
https://bugreports.qt.io/browse/QTBUG-91258

Strategy used by this code mainly focused on CJK language.
1. Japanese locale will group all Han script together.
   Katakana will be converted to hiragana.
2. Hangul will decompose and use consonant as group name.
3. Han will use icu "Han-Latin" transliteration to convert to pinyin.

BUG: 433297