Validations for Crm Lead from pack products

CHANGELOG:

### ADDED
- [#891](https://gitlab.com/coopdevs/odoo-somconnexio/-/merge_requests/891) Validations for Crm Lead from pack products

Related card: https://trello.com/c/fU2mfVRv/1414-validacions-a-nivell-de-producte-en-crmlead-de-packs

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