[FIX] web: click on an embedded pivot view cell does not causes a crash

The custom event 'open_view' triggered by the pivot
renderer was not stopped in the pivot controller. This
used to cause a crash because the dashboard controller
also listens to a custom event with the same name but
following another logic.
The present fix simply stop the propagaton of the event.
A test has been added in the module web_dashboard.

closes odoo/odoo#36466

Signed-off-by: Géry Debongnie (ged) <ged@openerp.com>

addons/web/static/src/js/views/pivot/pivot_controller.js

@@ -340,6 +340,7 @@ var PivotController = AbstractController.extend({
      * @param {OdooEvent} ev
      */
     _onOpenView: function (ev) {
+        ev.stopPropagation();
         var context = ev.data.context;
         var group = ev.data.group;
         var domain = this.model._getGroupDomain(group);