refactor: make data list reusable component

Closes #98

src/app/modules/data/data.provider.ts

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2018, 2019 StApps
+ * Copyright (C) 2018-2021 StApps
  * This program is free software: you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
  * Software Foundation, version 3.
@@ -31,7 +31,9 @@ export enum DataScope {
  * See https://angular.io/guide/dependency-injection for more info on providers
  * and Angular DI.
  */
-@Injectable()
+@Injectable({
+  providedIn: 'root',
+})
 export class DataProvider {
   /**
    * TODO