fix(serialize-xml): fix values in objects not permitted

commons-serialize-xml/src/main/java/io/gitlab/jfronny/commons/serialize/xml/wrapper/XmlWriter.java

@@ -199,6 +199,9 @@ public class XmlWriter extends SerializeWriter<IOException, XmlWriter> implement
     private void beforeValue() throws IOException {
         switch (peek()) {
             case DOCUMENT, ARRAY, OBJECT_VALUE_WRAPPER -> {}
+            case OBJECT -> {
+                if (deferredName == null) throw new IllegalStateException("Name not set.");
+            }
             default -> throw new IllegalStateException("Nesting problem.");
         }
     }