refactor: Result.hasMessage: iterate on all parent nub children

refs #302

src/util/result.ts

@@ -289,7 +289,7 @@ export class Result extends JalhydObject {
         }
 
         if (recurs && this._sourceNub !== undefined) {
-            for (const n of this._sourceNub.getChildren()) {
+            for (const n of this._sourceNub.allChildNubIterator()) {
                 if (n.result.hasMessage(code, true)) {
                     return true;
                 }