[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

docs/content-services/services/category-tree-datasource.service.md

@@ -0,0 +1,26 @@
+---
+Title: Category tree datasource service
+Added: v6.0.0.0
+Status: Active
+Last reviewed: 2023-01-25
+---
+
+# [Category tree datasource service](../../../lib/content-services/src/lib/category/services/category-tree-datasource.service.ts "Defined in category-tree-datasource.service.ts")
+
+Datasource service for category tree.
+
+## Class members
+
+### Methods
+
+-   **getSubNodes**(parentNodeId: `string`, skipCount?: `number`, maxItems?: `number`): [`Observable`](http://reactivex.io/documentation/observable.html)`<`[`TreeResponse<CategoryNode>`](../../../lib/content-services/src/lib/tree/models/tree-response.interface.ts)`>`<br/>
+    Gets categories as nodes for category tree.
+    -   _parentNodeId:_ `string`  - Identifier of a parent category
+    -   _skipCount:_ `number`  - Number of top categories to skip
+    -   _maxItems:_ `number`  - Maximum number of subcategories returned from Observable
+    -   **Returns** [`Observable`](http://reactivex.io/documentation/observable.html)`<`[`TreeResponse<CategoryNode>`](../../../lib/content-services/src/lib/tree/models/tree-response.interface.ts)`>` - TreeResponse object containing pagination object and list on nodes
+
+## Details
+
+Category tree datasource service acts as datasource for tree component utilizing category service. See the
+[Tree component](../../../lib/content-services/src/lib/tree/components/tree.component.ts) and [Tree service](../../../lib/content-services/src/lib/tree/services/tree.service.ts) to get more details on how datasource is used.