emojier: Fix `zh`(CN) being selected despite user's lang is `zh_TW` or `zh_HK`

Due to the format given by Qt is different from the file names that CLDR uses.
Original code: https://github.com/fcitx/fcitx5/blob/9f1412aceb58a7bcc14f71daa823da59926178ac/src/modules/emoji/emoji.cpp#L169

Changed `if` to `for` because: `zh_Hant_HK` needs `zh_Hant`, and (theoretically) `zh_Hant` needs `zh` (it actually doesn't).