Support xdg-usr-dirs 0.20 "Projects" folder

Version information

4.20.10

Debian forky/sid

Steps to reproduce

1. Run 'xdg-usr-dirs-update' using xdg-user-dirs 0.20
2. Open Thunar

Current behavior

Projects folder has a plain icon (I checked adwaita icons and papirus-icon-theme from the sid repos)

Expected outcome

The Projects folder should have a symbol, same as the other user-dirs directories

Backtrace

Additional information

Nautilus shows the correct icon. I know Thunar handles its icons differently, but it would be nice if there was visual unity in the Thunar home directory.