### Description

Only "search hits" based queries (no aggregations) provide a consistent view on the data when paginating through the result set. With point-in-time, it is possible to support transactional semantics for aggregation queries as well.

This issue is somewhat blocked by https://github.com/elastic/elasticsearch/issues/75528 because a PIT can not immediately be closed if the aggregation result set contains less than `fetch_size` records. This could cause some increased resource utilization due to open PITs. Especially if the client does not close the SQL cursor.
x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/analysis/CancellationTests.java
import org.elasticsearch.xpack.ql.type.DefaultDataTypeRegistry;
import org.elasticsearch.xpack.sql.SqlTestUtils;
import org.elasticsearch.xpack.sql.action.SqlQueryAction;
import org.elasticsearch.xpack.sql.action.SqlQueryRequest;
import org.elasticsearch.xpack.sql.action.SqlQueryRequestBuilder;
import org.elasticsearch.xpack.sql.action.SqlQueryResponse;
import org.elasticsearch.xpack.sql.action.SqlQueryTask;
import org.elasticsearch.xpack.sql.execution.PlanExecutor;
import org.elasticsearch.xpack.sql.plugin.TransportSqlQueryAction;
import org.elasticsearch.xpack.sql.proto.Mode;
import org.elasticsearch.xpack.sql.proto.SqlVersion;
import org.mockito.ArgumentCaptor;
import org.mockito.stubbing.Answer;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import static java.util.Collections.emptyMap;
import static java.util.Collections.singletonMap;
import static org.hamcrest.Matchers.instanceOf;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;
import static org.mockito.Mockito.when;
public class CancellationTests extends ESTestCase {