windows: enable window sharing

CMakeLists.txt

daemon

src/app/avadapter.cpp

src/app/avadapter.h

src/app/mainview/components/CallActionBar.qml

src/app/mainview/components/CallViewContextMenu.qml

src/app/mainview/components/ScreenRubberBand.qml

src/app/mainview/components/SelectScreen.qml

src/libclient/avmodel.cpp

src/libclient/callmodel.cpp

src/libclient/qtwrapper/videomanager_wrap.cpp

src/libclient/qtwrapper/videomanager_wrap.h