### Description

Clusters can have thousands of ILM policies. 
`GET _ilm/policy` returns all of them and runs on the master node.

This proposes we chunk the response for better memory usage and clients experience.

Relates to https://github.com/elastic/elasticsearch/issues/96568
x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ilm/action/GetLifecycleAction.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; you may not use this file except in compliance with the Elastic License
 * 2.0.
 */
package org.elasticsearch.xpack.core.ilm.action;
import org.elasticsearch.action.ActionRequestValidationException;
import org.elasticsearch.action.ActionResponse;
import org.elasticsearch.action.ActionType;
import org.elasticsearch.action.support.master.AcknowledgedRequest;
import org.elasticsearch.cluster.metadata.ItemUsage;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.tasks.CancellableTask;
import org.elasticsearch.tasks.Task;
import org.elasticsearch.tasks.TaskId;
import org.elasticsearch.xcontent.ToXContentObject;
import org.elasticsearch.xcontent.XContentBuilder;
import org.elasticsearch.xpack.core.ilm.LifecyclePolicy;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Objects;
public class GetLifecycleAction extends ActionType<GetLifecycleAction.Response> {