[ox] Remove need for explicit fields count in model system, add ox::String handler to OC

(synced from 2e9b7fe871)

src/ox/mc/read.hpp

@@ -8,6 +8,7 @@
 
 #pragma once
 
+#include <ox/model/fieldcounter.hpp>
 #include <ox/model/optype.hpp>
 #include <ox/model/types.hpp>
 #include <ox/std/byteswap.hpp>
@@ -87,7 +88,7 @@ class MetalClawReader {
 		StringLength stringLength(const char *name);
 
 		template<typename T = std::nullptr_t>
-		void setTypeInfo(const char *name = T::TypeName, int fields = T::Fields);
+		void setTypeInfo(const char *name = T::TypeName, int fields = countFields<T>());
 
 		/**
 		 * Returns a MetalClawReader to parse a child object.