Add ADL-based field traits, migrate all call sites, remove cafInternalPdmValueFieldSpecializations.h

Introduce cafPdmFieldTraits.h with ADL-based pdmToVariant/pdmFromVariant/pdmVariantEqual
as a replacement for PdmValueFieldSpecialization. Migrate all types (AppEnum, FilePath,
PdmPointer, cvf types) and all call sites (PdmDataValueField, PdmProxyValueField, UI
framework, ApplicationLibCode). Delete cafInternalPdmValueFieldSpecializations.h.
Add cafPdmFieldTraits unit tests and fix std::optional support.

ApplicationLibCode/Application/Tools/RiaOptionItemFactory.h

@@ -20,6 +20,7 @@
 
 #include "RifEclipseSummaryAddressDefines.h"
 
+#include "cafPdmOptionItemInfo.h"
 #include "cafPdmUiItem.h"
 
 #include <QList>