Fix/private products in catalog
⚠ Depends on !586 (merged) ⚠
CHANGELOG:
### Fixed
- [#615](https://gitlab.com/coopdevs/odoo-somconnexio/-/merge_requests/615) Add private field to private products in the catalog.
Related card: https://trello.com/c/kNivFzzs/944-la-t-conserva-trenca-lapi-del-cat%C3%A0leg
With this flag, we avoid exposing these products in the catalog API.
Edited by Pelayo García