Build on previous loop outputs with forward_iteration_output

Resolved a bug where each iteration of a Loop always received the original input rather than the output of the previous iteration, causing loops to repeat work instead of building on it. A new forward_iteration_output flag lets you explicitly opt in to passing each iteration's output forward as the next iteration's input.

Details**:**

• Fixes the default behavior where loop iterations were incorrectly re-receiving the original input
• Set forward_iteration_output=True to chain iteration outputs sequentially through the loop
• Default behavior remains unchanged for workflows that do not set the flag, preserving backward compatibility

See docs