Issue:
Swiss payslips count one extra absence day for employees without a working schedule. A one day accident leave can therefore be prorated as two days, reducing the regular wage and overstating the accident salary.

Steps to reproduce:
* Install Swiss Payroll.
* Configure a monthly employee without a working schedule.
* Assign one day of accident time off.
* Generate the payslip for that month.

Cause:
The Swiss wage computation derives absence boundaries from the date portion of the leave's UTC datetimes: https://github.com/odoo/enterprise/blob/16c29e1bab34b5bcb2b001477d928ec5eb294a97/l10n_ch_hr_payroll/models/hr_payslip.py#L313-L330

A fully flexible employee's full day leave starts at local midnight. In timezones ahead of UTC, that start is stored on the previous UTC date, so the inclusive calendar day computation adds an extra day.

Solution:
We need to use the requested time off dates for both payslip range filtering and absence proration. These fields preserve the calendar days selected by the user independently of timezone conversion, while leaving the UTC datetimes and half-day handling unchanged.

opw-6435086

Forward-Port-Of: odoo/enterprise#127513

1- The benefit fields related to the hr.version have a domain that limits them to the whitelisted fields used to copy values from a template, which does not always include benefit fields. The advantage of the whitelist is that it factored in for the allowed countries, so instead of duplicating this logic to benefit fields and implementing it in every l10n, we can check which module the field comes from.

example:
The field [`company_car_total_depreciated_cost`](https://github.com/odoo/enterprise/blob/ce691cd6aaacfb86cd866698d2fcc3fe930912cb/l10n_be_hr_payroll_fleet/models/hr_version.py#L62) cannot be selected as `res_field_id` when it should be possible as we see in the [data](https://github.com/odoo/enterprise/blob/ce691cd6aaacfb86cd866698d2fcc3fe930912cb/l10n_be_hr_contract_salary/data/hr_contract_salary_benefit_data.xml#L6), it is not whitelisted because we dont want to copy its value from a template.

2- Another fix is the inverse of the public field, there's a traceback because the selection field is always converted to a string and cannot be used to browse as is.
```py
  File "/data/build/enterprise/hr_contract_salary/models/hr_contract_salary_benefit.py", line 238, in _inverse_res_field_public
    record.res_field_id = self.sudo().env['ir.model.fields'].browse(record.res_field_public)
    ^^^^^^^^^^^^^^^^^^^
  File "/data/build/odoo/odoo/orm/fields.py", line 1890, in __set__
    write_value = self.convert_to_write(value, records)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/data/build/odoo/odoo/orm/fields_relational.py", line 387, in convert_to_write
    return value.id
           ^^^^^^^^
  File "/data/build/odoo/odoo/orm/fields_misc.py", line 115, in __get__
    raise ValueError("Expected singleton: %s" % record) from None
ValueError: Expected singleton: ir.model.fields('1', '7', '3', '8', '4')
```