feat: initialize language and date-format settings (#1214)

See: #1213

src/app/settings/settings.service.spec.ts

@@ -0,0 +1,12 @@
+import { TestBed } from '@angular/core/testing';
+
+import { SettingsService } from './settings.service';
+
+describe('SettingsService', () => {
+  beforeEach(() => TestBed.configureTestingModule({}));
+
+  it('should be created', () => {
+    const service: SettingsService = TestBed.get(SettingsService);
+    expect(service).toBeTruthy();
+  });
+});