Fix stringify error from resource deployment extension (#14059)

* Fix stringify error from resource deployment extension

* add comment

extensions/resource-deployment/src/common/utils.ts

@@ -71,3 +71,22 @@ export async function tryExecuteAction<T>(action: () => T | PromiseLike<T>): Pro
 	}
 	return { result, error };
 }
+
+export function deepClone<T>(obj: T): T {
+	if (!obj || typeof obj !== 'object') {
+		return obj;
+	}
+	if (obj instanceof RegExp) {
+		// See https://github.com/Microsoft/TypeScript/issues/10990
+		return obj as any;
+	}
+	const result: any = Array.isArray(obj) ? [] : {};
+	Object.keys(<any>obj).forEach((key: string) => {
+		if ((<any>obj)[key] && typeof (<any>obj)[key] === 'object') {
+			result[key] = deepClone((<any>obj)[key]);
+		} else {
+			result[key] = (<any>obj)[key];
+		}
+	});
+	return result;
+}