filter only by user from this app / company

[todo]

https://github.com/Gewaer/gewaer-cms-api/blob/7e898a2550fa8043a8a8ea368c15ec956c7fae47/api-publisher/controllers/UsersController.php#L63-L68

---

This issue was generated by todo based on a @todo comment in 7e898a2 when #52 was merged. cc @gewaer.