refactor: base event

Signed-off-by: Sebastian Krupinski <krupinski01@gmail.com>

core/lib/User/Event/UserEvent.php

@@ -61,6 +61,11 @@ abstract class UserEvent extends Event
         return $this->userIdentifier;
     }
 
+    public function tenantIdentifier(): string
+    {
+        return $this->tenantIdentifier;
+    }
+
     public function userIdentity(): string
     {
         return $this->userIdentity;