[PURIFY] remove all trace of x-pack watcher (#21)

This commit removes all trace of Elastic licensed watcher

buildSrc/src/test/java/org/elasticsearch/gradle/doc/RestTestFromSnippetsTaskTests.java

@@ -55,6 +55,5 @@ public void testEscapingInBlockQuote() {
     public void testIsDocWriteRequest() {
         assertTrue((boolean) RestTestsFromSnippetsTask.shouldAddShardFailureCheck("doc-index/_search"));
         assertFalse((boolean) RestTestsFromSnippetsTask.shouldAddShardFailureCheck("_cat"));
-        assertFalse((boolean) RestTestsFromSnippetsTask.shouldAddShardFailureCheck("_ml/datafeeds/datafeed-id/_preview"));
     }
 }

client/rest-high-level/src/main/java/org/elasticsearch/client/RestHighLevelClient.java

@@ -260,7 +260,6 @@ public class RestHighLevelClient implements Closeable {
     private final IngestClient ingestClient = new IngestClient(this);
     private final SnapshotClient snapshotClient = new SnapshotClient(this);
     private final TasksClient tasksClient = new TasksClient(this);
-    private final WatcherClient watcherClient = new WatcherClient(this);
     private final TransformClient transformClient = new TransformClient(this);
 
     /**
@@ -352,16 +351,6 @@ public final TasksClient tasks() {
         return tasksClient;
     }
 
-    /**
-     * Provides methods for accessing the Elastic Licensed Watcher APIs that
-     * are shipped with the default distribution of Elasticsearch. All of
-     * these APIs will 404 if run against the OSS distribution of Elasticsearch.
-     * <p>
-     * See the <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/watcher-api.html">
-     * Watcher APIs on elastic.co</a> for more information.
-     */
-    public WatcherClient watcher() { return watcherClient; }
-
     /**
      * Provides methods for accessing the Elastic Licensed Data Frame APIs that
      * are shipped with the Elastic Stack distribution of Elasticsearch. All of