[IMP] website: add countdown urlpicker placeholder

No default url on countdown's urlpicker anymore. Only a placeholder.
Also redirect to homepage if no url.

Part of: https://github.com/odoo/odoo/pull/46640



task-2210358

closes odoo/odoo#47235

X-original-commit: a0d983e94e3681a3f3e55cc445defc1ec862c606
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/website/static/src/snippets/s_countdown/000.js

@@ -94,7 +94,7 @@ const CountdownWidget = publicWidget.Widget.extend({
      */
     _handleEndCountdownAction: function () {
         if (this.endAction === 'redirect') {
-            const redirectUrl = this.el.dataset.redirectUrl;
+            const redirectUrl = this.el.dataset.redirectUrl || '/';
             if (this.hereBeforeTimerEnds) {
                 // Wait a bit, if the landing page has the same publish date
                 setTimeout(() => window.location = redirectUrl, 500);

addons/website/views/snippets/s_countdown.xml

@@ -29,7 +29,7 @@
             <we-checkbox string="Hide countdown at the end" data-dependencies="!no_end_action_opt"
                         data-select-class="hide-countdown"/>
             <we-urlpicker string="URL" data-dependencies="redirect_end_action_opt"
-                        data-select-data-attribute="/my-awesome-page" data-attribute-name="redirectUrl"/>
+                        data-select-data-attribute="" placeholder="e.g. /my-awesome-page" data-attribute-name="redirectUrl"/>
             <we-select string="Size" data-attribute-name="size">
                 <we-button data-select-data-attribute="80">Small</we-button>
                 <we-button data-select-data-attribute="120">Medium</we-button>