frontend: implement add/edit card

core/templates/widgets/err_banner.jinja

@@ -23,6 +23,10 @@ You must be logged in to preform this action
 Invalid serial number
 {% elif error == 11 %}
 Access Denied
+{% elif error == 12 %}
+Card already registered
+{% elif error == 13 %}
+AmusementIC Access Codes beginning with 5 must have IDm
 {% else %}
 An unknown error occoured
 {% endif %}