UI/UX - Blocks not visible on the TV page. (#626)

* Fix blocks not visible on the TV page.

* Add e2e testing for tv screen.

frontend/src/app/components/television/television.component.ts

@@ -4,6 +4,7 @@ import { OptimizedMempoolStats } from '../../interfaces/node-api.interface';
 import { StateService } from 'src/app/services/state.service';
 import { ApiService } from 'src/app/services/api.service';
 import { SeoService } from 'src/app/services/seo.service';
+import { Observable } from 'rxjs';
 
 @Component({
   selector: 'app-television',
@@ -11,7 +12,7 @@ import { SeoService } from 'src/app/services/seo.service';
   styleUrls: ['./television.component.scss']
 })
 export class TelevisionComponent implements OnInit {
-  loading = true;
+  isLoading$: Observable<boolean>;
 
   mempoolStats: OptimizedMempoolStats[] = [];
   mempoolVsizeFeesData: any;
@@ -26,11 +27,11 @@ export class TelevisionComponent implements OnInit {
   ngOnInit() {
     this.seoService.setTitle($localize`:@@46ce8155c9ab953edeec97e8950b5a21e67d7c4e:TV view`);
     this.websocketService.want(['blocks', 'live-2h-chart', 'mempool-blocks']);
+    this.isLoading$ = this.stateService.isLoadingWebSocket$;
 
     this.apiService.list2HStatistics$()
       .subscribe((mempoolStats) => {
         this.mempoolStats = mempoolStats;
-        this.loading = false;
       });
 
     this.stateService.live2Chart$