cli (call): implement GUI output: ``call`` commands now handle various output. Beside the original one (now named ``simple``), a new ``gui`` one display a full featured GUI (make with Qt). PyQt 6 or more needs to be installed. rel 427

#!/bin/sh

eval $(dbus-launch --sh-syntax)

nohup /usr/bin/Xtigervnc -geometry 1024x768 -desktop "Libervia e2e test" -rfbport 5900 -SecurityTypes None :0 &
nohup openbox &
exec libervia-backend fg