tdf#146619 Use more forward declarations in include/vcl/outdev.hxx

these were skipped in previous runs, since they contain some code behind #if

After inspecting these, it seems like the removals should not cause trouble.

This also shaves off some 140M input

Change-Id: Ie1f57174dd6fec3ba5b0b91eb0688acdc1a8143d
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/197494
Tested-by: Jenkins
Reviewed-by: Gabor Kelemen <gabor.kelemen@collabora.com>

forms/source/richtext/richtextcontrol.cxx

@@ -33,6 +33,7 @@
 #include <tools/debug.hxx>
 #include <comphelper/diagnose_ex.hxx>
 #include <sal/log.hxx>
+#include <vcl/rendercontext/SystemTextColorFlags.hxx>
 #include <vcl/svapp.hxx>
 
 #include <svx/svxids.hrc>