Description of the issue/feature this PR addresses:
Based on this feedback : [https://www.odoo.com/odoo/project.task/5436300 ](https://www.odoo.com/odoo/project.task/5436300%C2%A0)
When I got two versions with different working schedules, normally, in Attendance, the gant view should show the unavaibilities by putting in gray days you're not working.

As the feedback shows:-
. If you have two different working schedules on two different versions and two different occupations period (contract dates), it's working fine.
. If the two versions have the same occupation period (contract date), it's only considering the latest working schedule.
. If both versions are under the same contract, then it only shows the working schedule on the latest version. This is not what we expect 
Instead, it should show the correct working schedule for each period

Current behavior before PR:

Desired behavior after PR is merged:
. Modify _get_calendar_periods() method to return the correct working schedule for each period
. Fix version_date to use the specified date instead of the creation date.
. Add the corresponding tests

task-5473047

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Corrected the hardcoded string for the RIMPE Emprendedor regime to match the SRI structure

According to SRI technical specifications, the <contribuyenteRimpe> tag only accepts two specific values:
CONTRIBUYENTE RÉGIMEN RIMPE (Fixed value)
CONTRIBUYENTE NEGOCIO POPULAR - RÉGIMEN RIMPE

Steps to reproduce:

Install l10n_ec_edi module
Go to Settings > Invoicing > Ecuadorian Localization
In Electronic Invoicing > Regime, select rimpe_emprendedor
In Electronic Invoicing > Regime, configure a SRI Connection
Post an customer invoice

**Validation error occurring during the electronic signing process (using .p12 certificates):**
`35 - Se encontró el siguiente error en la estructura del comprobante: cvc-pattern-valid: Value 'CONTRIBUYENTE EMPRENDEDOR - RÉGIMEN RIMPE' is not facet-valid with respect to pattern 'CONTRIBUYENTE RÉGIMEN RIMPE|CONTRIBUYENTE NEGOCIO POPULAR - RÉGIMEN RIMPE' for type 'contribuyenteRimpe'.. - ARCHIVO NO CUMPLE ESTRUCTURA XML - ERROR `

Forward-Port-Of: odoo/enterprise#109147

**Steps to reproduce:
1. Create DE company (EUR currency)
2. Add USD -> EUR exchange rates for XX/01/26 and XX/15/26 (XX is target month)
3. Install l10n_de_reports
4. Make sure bank journal has 'outstanding receipts' set for incoming manual payment [Accounting -> Config -> Journals -> Bank]
5. Create USD invoice for XX/02/26 and confirm it
6. Register a Payment for XX/16/26 and confirm it (you should see the exchange difference entry matched alongside the payment)
7. Go to [Accounting -> Reporting -> General Ledger] and export DATEV data

**Description of issue:
The currency exchange rate difference entries in the exported file are shown as 0

**Expected behavior:
The actual currency exchange difference values should be displayed

**Why this happens?
The DATEV export currently sets the amount based on 'amount_currency'. For currency exchange difference entries, this value is 0.0 in the General Ledger, resulting in 0 values in the export.

**The fix:
Updated the logic to use the line balance when the entry is identified as a currency exchange difference.

opw-5358954

Forward-Port-Of: odoo/enterprise#109655
Forward-Port-Of: odoo/enterprise#107268