As we have the jitsi-meet-electron app, lets allow deployments to use it.

Allow deployments to enable desktop deeplinking without the need to re-implement _openDesktopApp()
Disable it by default to keep the current behaviour (deeplinking on mobile on, on desktop off)

This feature is meant as purely opt-in.

Signed-off-by: Christoph Settgast <csett86_git@quicksands.de>