feat(dashboard): direct link to single chart/tab/header in dashboard (#6964)

* direct display for pre-selected tab

* update parents

* add AnchorLink component

* add unit tests

superset/assets/spec/javascripts/dashboard/fixtures/mockDashboardData.js

@@ -0,0 +1,28 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+import { dashboardLayout } from './mockDashboardLayout';
+
+// mock the object to be posted to save_dash or copy_dash API
+export default {
+  css: '',
+  dashboard_title: 'Test 1',
+  default_filters: {},
+  expanded_slices: {},
+  positions: dashboardLayout.present,
+};