* fix(wechat_qrcode): Initialize nBytes after the count value is determined
* fix(wechat_qrcode): Incorrect count data repair
* chore: format expr
* fix(wechat_qrcode): Avoid null pointer exception
* fix(wechat_qrcode): return when bytes_ is empty
* test(wechat_qrcode): add test case
---------
Co-authored-by: GZTime <Time.GZ@outlook.com>