[ACS-4364] Move tree component and categories service to ADF (#8156)

* [ACS-4364] Add tree component and categories service

* [ACS-4364] Add tree component to public api

* [ACS-4364] Refine tree unit tests

* [ACS-4364] Intergrate adding and deleting category

* [ACS-4364] Restyle load more button in tree component

* [ACS-4364] Missing semicolon

* [ACS-4364] Fix code styling

* [ACS-4364] Add docs for tree component and category service

* [ACS-4364] CR fixes

* [ACS-4364] Hide header row when displayName is not provided

* [ACS-4364] Docs fixes

* [ACS-4364] Add helper methods, code cleanup, unit tests for new methods

* [ACS-4364] Add missing semicolon

lib/content-services/src/lib/tree/models/tree-node.interface.ts

@@ -0,0 +1,31 @@
+/*!
+ * @license
+ * Copyright 2019 Alfresco Software, Ltd.
+ *
+ * Licensed 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.
+ */
+
+export enum TreeNodeType {
+    RegularNode,
+    LoadMoreNode
+}
+
+export interface TreeNode {
+    id: string;
+    nodeName: string;
+    parentId: string;
+    level: number;
+    nodeType: TreeNodeType;
+    hasChildren: boolean;
+    isLoading: boolean;
+}