Separate core memory usage computation in core_memusage.h

src/script/script.cpp

@@ -260,8 +260,3 @@ std::string CScript::ToString() const
     }
     return str;
 }
-
-size_t CScript::DynamicMemoryUsage() const
-{
-    return memusage::DynamicUsage(*(static_cast<const std::vector<unsigned char>*>(this)));
-}