Feat(ContractHolderChangeWizard): change packs altogether

CHANGELOG:

### Changed
- [#1109](https://git.coopdevs.org/coopdevs/som-connexio/odoo-somconnexio/-/merge_requests/1109) Allow to change packs altogether with change holder wizard

Related card: https://trello.com/c/55T7x3ck/1605-odoo-canvis-de-titular

---