open string to file in new tab

workflows/templates/visualizations/string_to_file.html

 <div id="widgetvisualization-{{widget.pk}}" rel="{{widget.pk}}" class="widgetvisualizationdialog" title="{{widget.name}} visualization">
 <div style="width:400px;white-space:pre-wrap;font-family:monospace;">
 <pre style="width:400px !important;white-space:pre-wrap">
-<a href="{{MEDIA_URL}}{{output_dict.filename}}">Click here to access your file!</a>
+<a href="{{MEDIA_URL}}{{output_dict.filename}}" target="_blank">Click here to access your file!</a>
 </pre>
 </div>
 </div>
\ No newline at end of file