add urgent property to calendar entity

src/Bundle/ChillCalendarBundle/Entity/Calendar.php

@@ -203,6 +203,11 @@ class Calendar implements TrackCreationInterface, TrackUpdateInterface
      */
     private string $status = self::STATUS_VALID;
 
+    /**
+     * @ORM\Column(type="boolean", nullable=true)
+     */
+    private ?bool $urgent = false;
+
     public function __construct()
     {
         $this->comment = new CommentEmbeddable();