The side effect of `example/session_example.go`

After running `example/session_example.go`, you will notice the following databases appear in the IoTdb instance.

```
root@iotdb-service:/iotdb/sbin# show databases
bash: show: command not found
root@iotdb-service:/iotdb/sbin# ./start-cli.sh
---------------------
Starting IoTDB Cli
---------------------
_____ _________ ______ ______
|_ _| | _ _ ||_ _ `.|_ _ \
| | .--.|_/ | | \_| | | `. \ | |_) |
| | / .'`\ \ | | | | | | | __'.
_| |_| \__. | _| |_ _| |_.' /_| |__) |
|_____|'.__.' |_____| |______.'|_______/ version 2.0.5 (Build: 0917050)

Successfully login at 127.0.0.1:6667
IoTDB> show databases
+--------+-----------------------+---------------------+-------------------+---------------------+
|Database|SchemaReplicationFactor|DataReplicationFactor|TimePartitionOrigin|TimePartitionInterval|
+--------+-----------------------+---------------------+-------------------+---------------------+
|root.al1| 1| 1| 0| 604800000|
| root.ln| 1| 1| 0| 604800000|
|root.sg1| 1| 1| 0| 604800000|
+--------+-----------------------+---------------------+-------------------+---------------------+
Total line number = 3
It costs 0.025s
```

By default, there are no databases in an IoTdb instance. The databases mentioned in the previous output must have been created as a side effect of `example/session_example.go`.

In my personal opinion, for database testing, all test data should be completely deleted after the test ends.

This test clearly does not meet this requirement.

To avoid deleting existing business data, when inserting and deleting data, detection should also be added to avoid deleting existing devices with the same name or databases with the same name in the iotdb instance.

Start by reading and running example/session_example.go, then use the IoTDB CLI to reproduce the databases shown by `show databases`. Determine how its test data is inserted and deleted; done means the example leaves no test databases or devices behind while preserving pre-existing business data with matching names.

索引モデルが issue の本文から書いたものです。