add failing unit test for listbox issue #1936
add failing unit test for listbox issue #1936

grokys/Perspex,SuperJMN/Avalonia,SuperJMN/Avalonia,jkoritzinsky/Avalonia,wieslawsoltes/Perspex,wieslawsoltes/Perspex,AvaloniaUI/Avalonia,SuperJMN/Avalonia,wieslawsoltes/Perspex,AvaloniaUI/Avalonia,SuperJMN/Avalonia,wieslawsoltes/Perspex,AvaloniaUI/Avalonia,Perspex/Perspex,grokys/Perspex,SuperJMN/Avalonia,jkoritzinsky/Avalonia,AvaloniaUI/Avalonia,wieslawsoltes/Perspex,wieslawsoltes/Perspex,akrisiun/Perspex,SuperJMN/Avalonia,jkoritzinsky/Avalonia,Perspex/Perspex,AvaloniaUI/Avalonia,jkoritzinsky/Avalonia,SuperJMN/Avalonia,jkoritzinsky/Perspex,wieslawsoltes/Perspex,AvaloniaUI/Avalonia,jkoritzinsky/Avalonia,AvaloniaUI/Avalonia,jkoritzinsky/Avalonia,jkoritzinsky/Avalonia