Problem
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- The eco voucher button should be only displayed when a holiday termination payslip is in the batch. (N or/and N-1)
- When payslips are generated with the eco-voucher wizard, all payslips have the wrong structure : CP200HOLN. The eco voucher button should generate or regenerate a monthly payslip with the eco voucher inside.

Objective
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- Display the button for the good structures.
- Change the filtered employee in the eco-voucher wizard to match the structs
- Use the good struct for payslips generated from eco-voucher wizard : CP200MONTHLY
- Add new rule in the structure to display a line in the payslip if an eco-voucher is add as "other fields". (But hide it in the payslip)

Solution
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- Condition on structure code changed from CP200HOLN and CP200HOLN1 for the visibility of the eco voucher button.
- Employees filter changed for the eco-voucher action
- Payslip structure changed for payslips generated from the eco-voucher wizard.
- New record added in the CP200MONTHLY structure.

Test
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Python test added to test if an eco-vouchers line is added to payslips in the batch when the user validate the payslip generation from the eco-vouchers wizard.
3 cases are covered :
- generated payslips
- existing payslips
- edited existing payslips (edited with the edit payslip wizard in cogmenu)

task-3598939