Feat: Add the iteration Node #4242 (#4247)

### What problem does this PR solve?

Feat: Add the iteration Node #4242

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/flow/canvas/edge/index.tsx

@@ -90,6 +90,7 @@ export function ButtonEdge({
             // everything inside EdgeLabelRenderer has no pointer events by default
             // if you have an interactive element, set pointer-events: all
             pointerEvents: 'all',
+            zIndex: 1001, // https://github.com/xyflow/xyflow/discussions/3498
           }}
           className="nodrag nopan"
         >