statusicon: Use gtk_icon_helper_load_surface()
statusicon: Use gtk_icon_helper_load_surface()

This is in preparation for the next commit.

grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita