Added services and models

src/app/core/message/message-data-response.ts

@@ -0,0 +1,17 @@
+import { RemoteDataError } from '../data/remote-data-error';
+
+/**
+ * A class to represent the data retrieved by after processing a message
+ */
+export class MessageDataResponse {
+  constructor(
+    private isSuccessful: boolean,
+    public error?: RemoteDataError,
+    public payload?: any
+  ) {
+  }
+
+  get hasSucceeded(): boolean {
+    return this.isSuccessful;
+  }
+}