Fix concurrent asynchronous calls. (#675)

* Fix concurrent asynchronous calls.

* Remove test without mempool info websocket.

* Remove isloading$ variable.

frontend/src/app/components/blockchain-blocks/blockchain-blocks.component.ts

@@ -1,5 +1,5 @@
 import { Component, OnInit, OnDestroy, ChangeDetectionStrategy, ChangeDetectorRef, Input } from '@angular/core';
-import { Subscription, Observable } from 'rxjs';
+import { Subscription } from 'rxjs';
 import { Block } from 'src/app/interfaces/electrs.interface';
 import { StateService } from 'src/app/services/state.service';
 import { Router } from '@angular/router';
@@ -11,8 +11,7 @@ import { Router } from '@angular/router';
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class BlockchainBlocksComponent implements OnInit, OnDestroy {
-  @Input() isLoading$: Observable<boolean>;
-
+  
   network = '';
   blocks: Block[] = this.mountEmptyBlocks();
   markHeight: number;
@@ -23,6 +22,7 @@ export class BlockchainBlocksComponent implements OnInit, OnDestroy {
   blockStyles = [];
   interval: any;
   tabHidden = false;
+  loadingBlocks = false;
 
   arrowVisible = false;
   arrowLeftPx = 30;
@@ -54,6 +54,8 @@ export class BlockchainBlocksComponent implements OnInit, OnDestroy {
           return;
         }
 
+        this.loadingBlocks = true;
+
         if (this.blocks.length && block.height !== this.blocks[0].height + 1) {
           this.blocks = [];
           this.blocksFilled = false;