Summary: If the identity packet is split across two packets, then save it until we get a notification that more data is available for reading over the bluetooth link.
Test Plan: Connect a phone and laptop over Bluetooth, and verify that both the phone and laptop are able to see each other, and that either side can start and successfully go through the pairing process.
Reviewers: #kde_connect, mtijink
Reviewed By: #kde_connect, mtijink
Subscribers: mtijink, kdeconnect
Tags: #kde_connect
Differential Revision: https://phabricator.kde.org/D17789