[AAE-10125] Storybook stories for Comments component (#7741)

* [AAE-10125] Storybook stories for Comments component

* [AAE-10125] Storybook stories for Comments component

* Added missing type & defaultValue for nodeId prop

* Fixed MaterialModule imports

* Removed unnecessary module imports

* Created new Stories about comment with & without an avatar

* trigger travis

* travis fix

lib/core/services/comment-content.service.interface.ts

@@ -0,0 +1,24 @@
+/*!
+ * @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.
+ */
+
+import { Observable } from 'rxjs';
+import { CommentModel } from '../models/comment.model';
+
+export interface CommentContentServiceInterface {
+    addNodeComment(nodeId: string, message: string): Observable<CommentModel>;
+    getNodeComments(nodeId: string): Observable<CommentModel[]>;
+}