QIconLoader failed to find icon in hicolor

1. use chrome create a shorcut of website(chrome–menu–more tools–create shortcut）
2. desktop file path `~/.local/share/applications/chrome-fldmbijiogoemfecifgkfeoadboaboni-Profile_12.desktop`
3.  icon path `/home/mike/.local/share/icons/hicolor/16x16/apps`
4. QIcon::fromTheme("chrome-fldmbijiogoemfecifgkfeoadboaboni-Profile_12") got  iconName `chrome`  with path  `/usr/share/icons/Papirus/96x96/apps/chrome.svg`

Because libqtxdg adapts to Qt6 and is still on ` WIP` , xdgiconloader cannot be used to find icons in Qt6, and `QIconLoader` in Qt6 is already doing these things. But It  dashfallbacks in advance when searching for icons before searching for the complete iconname in hicolor.

https://github.com/lxqt/libqtxdg/pull/261 has fixed this issue