Set rows in virtualdesktop protocol

Summary: Uses D17691 and sets the info on the protocol

Test Plan: correct data sent

Reviewers: #plasma, #kwin, zzag

Reviewed By: #plasma, #kwin, zzag

Subscribers: zzag, graesslin, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D18293