Implement releasing of client-freed output

Summary:
Previously KWin supported only version 2 of wl_output interface
In third version there was an important addition that allowed clients to
unbind outputs they may previously have bound.

Bumping versions in both client and server part of KWayland to support
this behaviour.

Reviewers: davidedmundson, graesslin

Reviewed By: graesslin

Subscribers: jgrulich, #frameworks

Tags: #frameworks

Maniphest Tasks: T7785

Differential Revision: https://phabricator.kde.org/D10929