fdo#74424 Use Window::GetOutDev() to access ImplGetDPI(X|Y)()

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:
	include/vcl/window.hxx

Change-Id: I93c83578eb92cdf10c7009f98e91ab177879c141
Reviewed-on: https://gerrit.libreoffice.org/7788Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/source/window/window.cxx

@@ -9471,8 +9471,9 @@ void Window::ImplPaintToDevice( OutputDevice* i_pTargetOutDev, const Point& i_rP
     sal_Bool bDevOutput = mbDevOutput;
     mbDevOutput = true;
 
-    long nOldDPIX = ImplGetDPIX();
-    long nOldDPIY = ImplGetDPIY();
+    const OutputDevice *pOutDev = GetOutDev();
+    long nOldDPIX = pOutDev->ImplGetDPIX();
+    long nOldDPIY = pOutDev->ImplGetDPIY();
     mnDPIX = i_pTargetOutDev->ImplGetDPIX();
     mnDPIY = i_pTargetOutDev->ImplGetDPIY();
     sal_Bool bOutput = IsOutputEnabled();