prepare sending of plot requests

- values for query and date range were not
  propagated to the model

pdb-js/src/index.html

@@ -43,6 +43,10 @@
           },
         });
         
+        $('#search-date-range').on('apply.daterangepicker', function(ev, picker) {
+           const range = $('#search-date-range').val();
+           console.log("update date range: " + range);
+        });
     });
   </script>
 </body>