Add open on phone action to Itinerary reservations

Summary:
Enable sending reservations to the phone via KDE Connect. First, KDE Connect is queried for available devices (paired, connected, share plugin enabled). Then an action for each device is added. When triggering the action the transfer is initiated via DBus.
Possible improvements:

• Check if KDE Connect is recent enough/open functionality is available

Needs D15294 and D15293 to be functional

Test Plan: Open Lufthansa mail, click send to $device, check for Itinerary opening on device.

Reviewers: vkrause, mlaurent

Reviewed By: mlaurent

Subscribers: mlaurent, kde-pim

Tags: KDE PIM, KDE Itinerary

Differential Revision: https://phabricator.kde.org/D15467