feat: add one Enum of nodeState

web/src/main/java/seecoder/devcloud/web/service/impl/tree/TreeNodeServiceImpl.java

@@ -16,6 +16,7 @@ import seecoder.devcloud.web.dao.tree.TreeNodeMapper;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.List;
+import java.util.PriorityQueue;
 
 @Service
 public class TreeNodeServiceImpl implements TreeNodeService {