SWS-7: Finish "download" workflow template

Make it so the download workflow actually works and does things!

apps/web/src/app/workspaces/workspaces.component.html

 <div class="container-fluid">
   <div class="row py-2">
     <div class="col">
-      <button type="button" class="btn btn-primary" (click)="nullButtonOnClick()">Launch null capability [null -g]</button>
+      <button type="button" class="btn btn-primary" (click)="downloadButtonOnClick()">Launch null capability [null -g]</button>
     </div>
   </div>
 </div>