Non-unique node instance_id will be duplicated

[wangxye]

situation:

1. For a node entity, its name is uniquely indexed while instance_id is not;
2. As a result, there will be cases with the same name but different instance_ids;

mysql:

mysql> select * from node;
+----+---------------------------------------+------------------------------+-----------+----------+--------+-------------------+-------+---------------------+---------------------+
| id | name                                  | instance_id                  | volume_id | hostname | vpc_id | address           | epoch | create_time         | update_time         |
+----+---------------------------------------+------------------------------+-----------+----------+--------+-------------------+-------+---------------------+---------------------+
|  1 | automq-automq-for-rocketmq-broker-0   | automq-for-rocketmq-broker-0 | NULL      | NULL     | NULL   | 192.168.0.124:8081 |     0 | 2023-11-10 01:30:37 | 2023-11-26 14:43:15 |
|  2 | automq-automq-for-rocketmq-broker-1   | automq-for-rocketmq-broker-1 | NULL      | NULL     | NULL   | 192.168.5.36:8081  |     0 | 2023-11-10 01:30:38 | 2023-11-26 14:43:34 |
|  3 | automq-for-rocketmq-rocketmq-broker-0 | rocketmq-broker-0            | NULL      | NULL     | NULL   | 192.168.4.209:8081 |     0 | 2023-11-30 03:14:48 | 2023-12-04 08:58:39 |
+----+---------------------------------------+------------------------------+-----------+----------+--------+-------------------+-------+---------------------+---------------------+

broker log:

java.sql.SQLIntegrityConstraintViolationException: Duplicate entry 'automq-for-rocketmq-rocketmq-broker-0' for key 'node.idx_name'