Entities cleanup, Primitive concept introduced

js/entity/primitive/ObjectReference.js

@@ -0,0 +1,23 @@
+import Primitive from "./Primitive"
+
+export default class ObjectReference extends Primitive {
+
+    /**
+     * 
+     * @param {String} type 
+     * @param {String} path 
+     */
+    constructor(type, path) {
+        super()
+        this.type = type
+        this.path = path
+    }
+
+    toString() {
+        return (this.type ?? "") + (
+            this.path
+                ? this.type ? `'"${this.path}"'` : this.path
+                : ""
+        )
+    }
+}