feat: add components for external services (#376)

- Add sms and edit-sms component
- Add notification and edit-notification component
- Add email and edit-email component
- Add amazon-s3 and edit-amazon-s3 component

Fixes: #182 and Fixes: #183

src/app/system/external-services/email/email.resolver.ts

@@ -0,0 +1,30 @@
+/** Angular Imports */
+import { Injectable } from '@angular/core';
+import { Resolve } from '@angular/router';
+
+/** rxjs Imports */
+import { Observable } from 'rxjs';
+
+/** Custom Services */
+import { SystemService } from '../../system.service';
+
+/**
+ * Email Configuration data resolver.
+ */
+@Injectable()
+export class EmailConfigurationResolver implements Resolve<Object> {
+
+  /**
+   * @param {SystemService} systemService System service.
+   */
+  constructor(private systemService: SystemService) {}
+
+  /**
+   * Returns the Email Configuration data.
+   * @returns {Observable<any>}
+   */
+  resolve(): Observable<any> {
+    return this.systemService.getExternalConfiguration('SMTP');
+  }
+
+}