[ADF-3041] TaskList Component - Empty State issue. (#3345)

* [DW-635] Empty State Component

* [DW-635] Empty State Component

* [DW-635] Empty state Issue

* [DW-635] Use empty state component and custom empty directive

* [ADF-3041] Documentation for TaskList Component - Empty State issue.

lib/core/datatable/directives/empty-custom-content.directive.ts

@@ -0,0 +1,24 @@
+/*!
+ * @license
+ * Copyright 2016 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.
+ */
+
+import { Directive } from '@angular/core';
+
+@Directive({
+    selector: 'adf-empty-custom-content'
+})
+
+export class EmptyCustomContentDirective {}