Fix hexadecimal conversion to show leading zeros.

Fixes #2805.

frontend/src/app/shared/pipes/decimal2hex/decimal2hex.pipe.ts

@@ -5,6 +5,6 @@ import { Pipe, PipeTransform } from '@angular/core';
 })
 export class Decimal2HexPipe implements PipeTransform {
   transform(decimal: number): string {
-    return `0x` + decimal.toString(16);
+    return `0x` + ( decimal.toString(16) ).padStart(8, '0');
   }
 }