This makes KWin switch to in-tree copy of KWaylandServer codebase.
KWaylandServer namespace has been left as is. It will be addressed later
by renaming classes in order to fit in the KWin namespace.
Currently, we have a mix of Frameworks versions and Plasma versions in
@since tags, which leads to some confusion. Since this is an unstable
library, one cannot rely on since version tags, we are free to add,
change, and remove apis to serve best to kwin requirements. Thus, we can
simply remove all since version tags to fix mixing up different product
versions.
The current xdg-shell wrappers don't match existing abstractions in the
xdg-shell protocol well, which makes it more difficult to refactor code
that is responsible for managing configure events and geometry in kwin.
Given that the xdg_decoration and the xdg_shell protocols are tightly
coupled together, I had to rewrite our wrappers for the xdg_decoration
protocol as well.
