[CST-5341] Link back to the item page in the now downloading page

src/app/shared/bitstream-download-page/bitstream-download-page.component.html

@@ -1,3 +1,8 @@
 <div class="container">
+  <div class="d-flex justify-content-between">
     <h3>{{'bitstream.download.page' | translate:{bitstream: (bitstream$ | async)?.name} }}</h3>
+    <button (click)="back()" class="btn btn-outline-secondary">
+      <i class="fas fa-arrow-left"></i> {{'bitstream.download.page.back' | translate}}
+    </button>
+  </div>
 </div>

src/app/shared/bitstream-download-page/bitstream-download-page.component.ts

@@ -12,6 +12,7 @@ import { FileService } from '../../core/shared/file.service';
 import { HardRedirectService } from '../../core/services/hard-redirect.service';
 import { getForbiddenRoute } from '../../app-routing-paths';
 import { RemoteData } from '../../core/data/remote-data';
+import { Location } from '@angular/common';
 
 @Component({
   selector: 'ds-bitstream-download-page',
@@ -33,10 +34,15 @@ export class BitstreamDownloadPageComponent implements OnInit {
     private auth: AuthService,
     private fileService: FileService,
     private hardRedirectService: HardRedirectService,
+    private location: Location,
   ) {
 
   }
 
+  back(): void {
+    this.location.back();
+  }
+
   ngOnInit(): void {
 
     this.bitstreamRD$ = this.route.data.pipe(

src/assets/i18n/en.json5

@@ -551,6 +551,7 @@
 
   "bitstream.download.page": "Now downloading {{bitstream}}..." ,
 
+  "bitstream.download.page.back": "Back" ,
 
 
   "bitstream.edit.authorizations.link": "Edit bitstream's Policies",