Add a base for testing iterator step in frontend. Loop next step ids need to be added to an input since the loop handle does not exist on the step yet. Here is an example of run: <img width="1271" height="653" alt="Capture d’écran 2025-09-01 à 16 21 39" src="https://github.com/user-attachments/assets/06ecf981-be17-4d31-84f6-11c2cc98cb66" /> First create record in the loop name is `{{currentItem}} - first`, the second is `{{currentItem}} - second` <img width="276" height="326" alt="Capture d’écran 2025-09-01 à 16 22 25" src="https://github.com/user-attachments/assets/0ae03b65-aeda-41a6-8693-c17711ec2102" />