Remove all unused imports and fix CRLF (#31207)

The X-Pack opening and the recent other refactorings left a lot of 
unused imports in the codebase. This commit removes them all.

Author: tlrx

client/benchmark/src/main/java/org/elasticsearch/client/benchmark/AbstractBenchmark.java

@@ -28,8 +28,6 @@
 import java.lang.management.GarbageCollectorMXBean;
 import java.lang.management.ManagementFactory;
 import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 

client/rest-high-level/src/test/java/org/elasticsearch/client/RequestConvertersTests.java

@@ -30,7 +30,6 @@
 import org.elasticsearch.action.ActionRequestValidationException;
 import org.elasticsearch.action.DocWriteRequest;
 import org.elasticsearch.action.admin.cluster.node.tasks.cancel.CancelTasksRequest;
-import org.elasticsearch.action.admin.cluster.node.tasks.cancel.CancelTasksResponse;
 import org.elasticsearch.action.admin.cluster.node.tasks.list.ListTasksRequest;
 import org.elasticsearch.action.admin.cluster.repositories.delete.DeleteRepositoryRequest;
 import org.elasticsearch.action.admin.cluster.repositories.get.GetRepositoriesRequest;
@@ -99,7 +98,6 @@
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentType;
-import org.elasticsearch.common.xcontent.json.JsonXContent;
 import org.elasticsearch.index.RandomCreateIndexGenerator;
 import org.elasticsearch.index.VersionType;
 import org.elasticsearch.index.query.TermQueryBuilder;

client/rest-high-level/src/test/java/org/elasticsearch/client/SnapshotIT.java

@@ -19,8 +19,6 @@
 
 package org.elasticsearch.client;
 
-import org.apache.http.entity.ContentType;
-import org.apache.http.entity.StringEntity;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.action.admin.cluster.repositories.delete.DeleteRepositoryRequest;
 import org.elasticsearch.action.admin.cluster.repositories.delete.DeleteRepositoryResponse;
@@ -35,7 +33,6 @@
 import org.elasticsearch.rest.RestStatus;
 
 import java.io.IOException;
-import java.util.Collections;
 
 import static org.hamcrest.Matchers.equalTo;
 

client/rest/src/test/java/org/elasticsearch/client/RequestTests.java

@@ -19,7 +19,6 @@
 
 package org.elasticsearch.client;
 
-import org.apache.http.Header;
 import org.apache.http.HttpEntity;
 import org.apache.http.entity.ByteArrayEntity;
 import org.apache.http.entity.ContentType;
@@ -29,9 +28,7 @@
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 
 import static org.junit.Assert.assertEquals;

distribution/archives/integ-test-zip/src/test/java/org/elasticsearch/test/rest/CreatedLocationHeaderIT.java

@@ -23,7 +23,6 @@
 import org.apache.http.entity.StringEntity;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.Response;
-import org.junit.Before;
 
 import java.io.IOException;
 

distribution/tools/plugin-cli/src/main/java/org/elasticsearch/plugins/ListPluginsCommand.java

@@ -23,19 +23,15 @@
 import org.elasticsearch.Version;
 import org.elasticsearch.cli.EnvironmentAwareCommand;
 import org.elasticsearch.cli.Terminal;
-import org.elasticsearch.common.Nullable;
 import org.elasticsearch.env.Environment;
 
 import java.io.IOException;
 import java.nio.file.DirectoryStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
-import java.util.Set;
-import java.util.stream.Collectors;
 
 /**
  * A command for the plugin cli to list plugins installed in elasticsearch.

distribution/tools/plugin-cli/src/main/java/org/elasticsearch/plugins/PluginCli.java

@@ -22,7 +22,6 @@
 import org.elasticsearch.core.internal.io.IOUtils;
 import org.elasticsearch.cli.Command;
 import org.elasticsearch.cli.LoggingAwareMultiCommand;
-import org.elasticsearch.cli.MultiCommand;
 import org.elasticsearch.cli.Terminal;
 
 import java.io.IOException;

distribution/tools/plugin-cli/src/test/java/org/elasticsearch/plugins/RemovePluginCommandTests.java

@@ -23,7 +23,6 @@
 import org.elasticsearch.Version;
 import org.elasticsearch.cli.ExitCodes;
 import org.elasticsearch.cli.MockTerminal;
-import org.elasticsearch.cli.Terminal;
 import org.elasticsearch.cli.UserException;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;

libs/core/src/main/java/org/elasticsearch/common/unit/TimeValue.java

@@ -19,7 +19,6 @@
 
 package org.elasticsearch.common.unit;
 
-import java.io.IOException;
 import java.util.Locale;
 import java.util.Objects;
 import java.util.concurrent.TimeUnit;

libs/grok/src/test/java/org/elasticsearch/grok/GrokTests.java

@@ -22,7 +22,6 @@
 import org.elasticsearch.test.ESTestCase;
 import org.junit.Before;
 
-import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;