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/StartNode.tsx

@@ -25,8 +25,6 @@ export default function StartNode(props: NodeProps<Node>) {
         <div className={"flex-row gap-sm"}>
           Start
         </div>
-        <Handle type="target" position={Position.Left} id="target"/>
-        <Handle type="target" position={Position.Bottom} id="norms"/>
         <Handle type="source" position={Position.Right} id="source"/>
       </div>
     </>