Change the get data stream api to include the following properties of a data stream:

- ~~Add `index_mode` from `DataStream` to the response.~~
- For each backing index of a data stream with time series index mode, include the temporal range the backing index represents (based on the `index.time_series.start_time` and `index.time_series.end_time` index settings.
modules/data-streams/src/test/java/org/elasticsearch/datastreams/action/GetDataStreamsResponseTests.java
/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
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package org.elasticsearch.datastreams.action;
import org.elasticsearch.action.datastreams.GetDataStreamAction.Response;
import org.elasticsearch.cluster.health.ClusterHealthStatus;
import org.elasticsearch.cluster.metadata.DataStreamTestHelper;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.test.AbstractWireSerializingTestCase;
import java.util.ArrayList;
import java.util.List;
public class GetDataStreamsResponseTests extends AbstractWireSerializingTestCase<Response> {