Add setting to enable / disable barcode support

(Default = True)

InvenTree/templates/InvenTree/settings/global.html

@@ -21,4 +21,12 @@
     </tbody>
 </table>
 
+<h4>{% trans "Barcode Settings" %}</h4>
+<table class='table table-striped table-condensed'>
+    {% include "InvenTree/settings/header.html" %}
+    <tbody>
+        {% include "InvenTree/settings/setting.html" with key="BARCODE_ENABLE" icon="fa-qrcode" %}
+    </tbody>
+</table>
+
 {% endblock %}