Use libportal to call background portal
At the moment the request portal wrapper is using the application id as
a window identifier. This is an invalid window identifier, this string
should start with either x11:
or wayland:
. See [1].
There is a related report at [2].
[1] https://flatpak.github.io/xdg-desktop-portal/docs/window-identifiers.html
Edited by Maximiliano