core (launcher): new `wait_for_service` option: if `wait_for_service` is used in `[DEFAULT]`, the service at the specified host/port is waited for before starting the backend. This is useful in the situation where we need to be sure that something is started before running, e.g. in a container.

#!/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