fdo#74424 Use Window::GetOutDev() to access ImplHasMirroredGraphics()

Part of the decoupling of Window from OutputDevice. We now get
the Window's OutputDevice instance and manipulate this. Do not rely
on the inherited function.

Conflicts:
	vcl/source/window/window.cxx

Change-Id: If429486dee4f7cc1e55ca48ab5d715d0c30578a3
Reviewed-on: https://gerrit.libreoffice.org/7794
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>