Fix auto-search when changing the select in nuxeo-date-picker

Steps to reproduce:

1. define a page provider with a "date" field

           <predicate parameter="dc:created" operator="&gt;=">
             <field schema="advanced_search" name="dublincore_created"/>
           </predicate>
   

2. define a search for with a nuxeo-date-picker element

       <nuxeo-date-picker value="{{params.dublincore_created}}" label="Created from" name="dublincore_created" role="widget"></nuxeo-date-picker>
   

3. deploy the Studio package with these changes
4. Go to the Search form
5. select a date with the nuxeo-date-picker element "Created from"
6. observe the results are refreshed
7. change the selected date in the field "Created from"
8. observe that nothing happens

Expected behavior:
changing the value in the nuxeo-date-picker element should trigger the update of the results

Workaround:
Remove the value and then select a new one => the results are updated