Added first seen on mempool transactions.

frontend/src/app/components/latest-blocks/latest-blocks.component.html

@@ -11,7 +11,7 @@
     <tr *ngFor="let block of blocks; let i= index; trackBy: trackByBlock">
       <td><a [routerLink]="['/block', block.id]" [state]="{ data: { block: block } }">#{{ block.height }}</a></td>
       <td class="d-none d-md-block">{{ block.timestamp * 1000 | date:'yyyy-MM-dd HH:mm' }}</td>
-      <td>{{ block.timestamp | timeSince : trigger }} ago</td>
+      <td><app-time-since [time]="block.timestamp" [fastRender]="true"></app-time-since> ago</td>
       <td>{{ block.tx_count }}</td>
       <td>{{ block.size | bytes: 2 }}</td>
       <td class="d-none d-md-block">