game state can be read out by the client APIs

# Conflicts:
#	front/src/Api/IframeListener.ts
#	front/src/Phaser/Game/GameScene.ts
#	front/src/iframe_api.ts

front/src/utility.ts

@@ -0,0 +1,18 @@
+export function deepFreezeClone<T> (obj:T):Readonly<T> {
+    return deepFreeze(JSON.parse(JSON.stringify(obj)));
+}
+
+function deepFreeze<T> (obj:T):T{
+  Object.freeze(obj);
+  if (obj === undefined) {
+    return obj;
+  }
+  const propertyNames = Object.getOwnPropertyNames(obj) as Array<keyof T>;
+  propertyNames.forEach(function (prop) {
+    if (obj[prop] !== null&& (typeof obj[prop] === "object" || typeof obj[prop] === "function") && !Object.isFrozen(obj[prop])) {
+      deepFreezeClone(obj[prop]);
+    }
+  });
+
+  return obj;
+}