refactor: rename DTree to DValue

site/demo/unit-info.uce

@@ -3,7 +3,7 @@
 RENDER(Request& context)
 {
 	bool allow_mutation = test_demo_request_allowed(context);
-	DTree payload;
+	DValue payload;
 
 	if(context.get["compile"] != "")
 	{
@@ -19,11 +19,11 @@ RENDER(Request& context)
 
 	payload["current"] = unit_info();
 
-	DTree units;
+	DValue units;
 	units.set_array();
 	for(auto& unit_path : units_list())
 	{
-		DTree item;
+		DValue item;
 		item = unit_path;
 		units.push(item);
 	}