[Subtask] Add Partition APIs in Gravitino Python client

### Describe the subtask

Add these Python function interfaces into Gravitino Python client, reference to the document for the API descriptions.

+ listPartitions(...): https://datastrato.ai/docs/0.4.0/api/rest/list-partitions
+ addPartition(...): https://datastrato.ai/docs/0.4.0/api/rest/add-partitions
+ getPartition(...): https://datastrato.ai/docs/0.4.0/api/rest/get-partition

We can reference the Gravitino JAVA client implementation, [RelationalTable.java](https://github.com/datastrato/gravitino/blob/main/clients/client-java/src/main/java/com/datastrato/gravitino/client/RelationalTable.java)

### Parent issue

#2113

Start with the three REST API descriptions for listPartitions, addPartition, and getPartition, then compare their interfaces with the Java client implementation in RelationalTable.java. Done means the Gravitino Python client exposes all three functions with behavior matching the documented APIs.

Written by the indexing model from the issue text.