chore: merge the rest of the nodes back into this structure, and make sure that start and end nodes are not deletable.

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

@@ -18,7 +18,7 @@ export type EndNode = Node<EndNodeData>
 export default function EndNode(props: NodeProps<Node>) {
   return (
     <>
-      <Toolbar nodeId={props.id} allowDelete={true}/>
+      <Toolbar nodeId={props.id} allowDelete={false}/>
       <div className={`${styles.defaultNode} ${styles.nodeEnd}`}>
         <div className={"flex-row gap-sm"}>
         End