IDL defined commands currently call either IDLParserContext::parseNSCollectionRequired or IDLParserContext::parseNsOrUUID to construct the namespace for the command. IDLParserContext is meant to be lower in the dependency graph than NamespaceStringUtil, and so it cannot link NamespaceStringUtil's lib. There's no specific need to construct the namespaces through IDLParseContext, so in this ticket, we can change struct_types.py to call NamespaceStringUtil::parse... directly instead.