refactor: make sure that the droppable styles are kept, update some nodes to reflect their used functionality.

ref: N25B-294

src/pages/VisProgPage/visualProgrammingUI/nodes/PhaseNode.tsx

@@ -13,6 +13,7 @@ import { NodeDefaults, NodeReduces } from '../NodeRegistry';
  * @param label: the label of this phase
  * @param droppable: whether this node is droppable from the drop bar (initialized as true)
  * @param children: ID's of children of this node
+ * @param hasReduce: whether this node has reducing functionality (true by default)
  */
 export type PhaseNodeData = {
   label: string;
@@ -43,7 +44,6 @@ export default function PhaseNode(props: NodeProps<Node>) {
         <Handle type="target" position={Position.Left} id="target"/>
         <Handle type="source" position={Position.Right} id="source"/>
         <Handle type="source" position={Position.Bottom} id="norms"/>
-        <Handle type="source" position={Position.Top} id="norms"/>
       </div>
     </>
   );