use libkeepalive to wakeup daemon

Summary:
Main change is to use libkeepalive to wake up the system to ensure connections stay alive

Other minor changes are:
-Log daemon messages for debugging purposes
-Add way to forece refresh of device list
-Minor spec improvements

The keepalive changes certainly seem to help, not sure if it completely solves the problems
The logging changes are temporary, and I could use them locally, but they only affect sailfish users
Im not sure if the refresh method is correct, but seems to force the daemon to check for devices

Reviewers: KDE Connect, nicolasfella, albertvaka

Reviewed By: KDE Connect, albertvaka

Subscribers: kdeconnect

Tags: KDE Connect

Differential Revision: https://phabricator.kde.org/D15414