Fixing missing assets data for Liquid Testnet native asset

fixes #1068

frontend/src/app/services/assets.service.ts

@@ -1,7 +1,7 @@
 import { Injectable } from '@angular/core';
 import { HttpClient } from '@angular/common/http';
 import { Observable } from 'rxjs';
-import { shareReplay, switchMap } from 'rxjs/operators';
+import { map, shareReplay, switchMap } from 'rxjs/operators';
 import { StateService } from './state.service';
 
 @Injectable({
@@ -29,6 +29,13 @@ export class AssetsService {
     this.getAssetsMinimalJson$ = this.stateService.networkChanged$
     .pipe(
       switchMap(() => this.httpClient.get(`${apiBaseUrl}/resources/assets${this.stateService.network === 'liquidtestnet' ? '-testnet' : ''}.minimal.json`)),
+      map((assetsMinimal) => {
+        if (this.stateService.network === 'liquidtestnet') {
+          // Hard coding the Liquid Testnet native asset
+          assetsMinimal['144c654344aa716d6f3abcc1ca90e5641e4e2a7f633bc09fe3baf64585819a49'] = [null, "tL-BTC", "Test Liquid Bitcoin", 8];
+        }
+        return assetsMinimal;
+      }),
       shareReplay(1),
     );
     this.getMiningPools$ = this.httpClient.get(apiBaseUrl + '/resources/pools.json').pipe(shareReplay(1));