Add serial number and EISA ID to OutputDevice interface

Reviewers: graesslin, sebas, #kwin, dvratil, romangg

Reviewed By: #kwin, romangg

Subscribers: romangg, kde-frameworks-devel, davidedmundson, plasma-devel

Tags: #plasma_on_wayland, #frameworks

Differential Revision: https://phabricator.kde.org/D10040