imp: add open off canvas form ajax command

js/druplan.js

+/**
+ * @file
+ * Fullcalendar View plugin JavaScript file.
+ */
+
+// Jquery wrapper for drupal to avoid conflicts between libraries.
+(function ($, Drupal) {
+
+  Drupal.AjaxCommands.prototype.openOffCanvasForm = function (ajax, response, status) {
+    let modal_settings = {
+      // url: viewSettings['response.url'] + "?start=" + slotDate + "&destination=" + window.location.pathname,
+      url: response.url,
+      dialogType: 'dialog',
+      dialogRenderer: 'off_canvas',
+      dialog: {
+        width: 'fit-content', classes: {'ui-dialog': 'druplan-dialog druplan-dialog-off-canvas'}
+      },
+    };
+    Drupal.ajax(modal_settings).execute();
+  }
+
+})(jQuery, Drupal);