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.
Some tests need it, e.g.
FAIL! : TestXdgShellClient::testDesktopFileName() Compared values are not the same
Actual (c->icon().name()) : ""
Expected (QStringLiteral("wayland")): "wayland"
Some tests need it, e.g.
FAIL! : TestDontCrashUseractionsMenu::initTestCase() 'kwinApp()->setStyle(QStringLiteral("breeze"))' returned FALSE. ()
Loc: [/builds/plasma/kwin/autotests/integration/dont_crash_useractions_menu.cpp(57)]