Add context key to search by partner children in contracts
CHANGELOG:
### CHANGED
- [#469](https://gitlab.com/coopdevs/odoo-somconnexio/-/merge_requests/469) Looking for partners' submails too in contract search
Edited by Pelayo García
CHANGELOG:
### CHANGED
- [#469](https://gitlab.com/coopdevs/odoo-somconnexio/-/merge_requests/469) Looking for partners' submails too in contract search