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

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: Ia68ba25a9d42ce653c093dbea7087ab8431c8509
Reviewed-on: https://gerrit.libreoffice.org/7795
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>