Add rows info to the plasma virtual desktop protocol
Summary:
in order for the pager to work correctly and not having to use a weird mix of wayland and dbus apis, the rows
number needs to be in the protocol
Test Plan: new passing autotest
Reviewers: Plasma, KWin, davidedmundson
Reviewed By: Plasma, KWin, davidedmundson
Subscribers: zzag, davidedmundson, hein, kde-frameworks-devel
Tags: Frameworks
Maniphest Tasks: T4457
Differential Revision: https://phabricator.kde.org/D17691