[ADF-741] Add the create task attachment component to the demo shell (#1946)

* Add the create task attachment component to the demo shell

* Add translation keys

* Add return to methods

ng2-components/ng2-activiti-tasklist/src/components/adf-task-attachment-list.component.ts

@@ -55,10 +55,14 @@ export class TaskAttachmentListComponent implements OnChanges {
         }
     }
 
-    reset () {
+    reset(): void {
         this.attachments = [];
     }
 
+    reload(): void {
+        this.loadAttachmentsByTaskId(this.taskId);
+    }
+
     private loadAttachmentsByTaskId(taskId: string) {
         if (taskId) {
             this.reset();