test: create universal tests and rewrite nodes to have optional parameters for more code coverage

ref: N25B-362

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

@@ -78,8 +78,10 @@ export function PhaseReduce(node: Node, nodes: Node[]) {
         .filter(([t]) => !nodesNotInPhase.includes(t))
         .map(([t]) => t);
 
-    // children nodes
-    const childrenNodes = nodes.filter((node) => data.children.includes(node.id));
+    // children nodes - make sure to check for empty arrays
+    let childrenNodes: any[] = [];
+    if (data.children) 
+      childrenNodes = nodes.filter((node) => data.children.includes(node.id));
 
     // Build the result object
     const result: Record<string, unknown> = {