[ACA-4382 ] About Page refactoring to use it across all the platform (#7365)

* about page refactor for global usage

* Development About

* add storybook

* fix build

* fix

* fix

* fix imports

* fix

* fix lint

* fix

* fix

* fix

* fix

lib/extensions/src/lib/mock/app-extension.service.mock.ts

@@ -0,0 +1,39 @@
+/*!
+ * @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 { Injectable } from '@angular/core';
+import { ExtensionRef } from '../config/extension.config';
+import { Observable, BehaviorSubject } from 'rxjs';
+import { ViewerExtensionRef } from '../config/viewer.extensions';
+
+@Injectable({
+    providedIn: 'root'
+})
+export class AppExtensionServiceMock {
+    private _references = new BehaviorSubject<ExtensionRef[]>([]);
+
+    references$: Observable<ExtensionRef[]>;
+
+    constructor() {
+        this.references$ = this._references.asObservable();
+    }
+
+    getViewerExtensions(): ViewerExtensionRef[] {
+        return [];
+    }
+
+}

lib/extensions/src/lib/mock/public-api.ts

@@ -0,0 +1,18 @@
+/*!
+ * @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 * from './app-extension.service.mock';

lib/extensions/src/public-api.ts

@@ -41,3 +41,5 @@ export * from './lib/store/states/repository.state';
 
 export * from './lib/components/public-api';
 export * from './lib/extensions.module';
+
+export * from './lib/mock/public-api';