Fix mobile_contract_search_view

The search tag has recently been added to mobile_contract_search_view making the inherited filters to stop working. Moving them out of the tag fixes this.

CHANGELOG:

### Fixed
- [#678](https://gitlab.com/coopdevs/odoo-somconnexio/-/merge_requests/678) Fix name searching in `mobile_contract_search_view` 

Related card: https://trello.com/c/zMHYCMVN/1034-revisar-filtre-contractes-m%C3%B2bil-alta-prioritat

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