Add Theroretical Hours End Date and historic for Working Hours

CHANGELOG:

### ADDED
- [#814](https://gitlab.com/coopdevs/odoo-somconnexio/-/merge_requests/814) Add Theroretical Hours End Date and historic for Working Hours

Related card: https://trello.com/c/T04w4Re7/1262-rrhh-cambios-en-contrato-de-trabajo

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