This pull request introduces improvements to the handling of Chilean electronic document sequences, enforces stricter validation for certificate data, and modernizes string formatting throughout the codebase. The most significant changes focus on ensuring that document folio numbers are correctly managed in accordance with available CAFs, making the certificate model more robust, and updating code style for clarity and consistency.

This improvement is mostly made because CAFs have expiration dates and fixed folio numbers. If the expiration date is reached but the folios were not fully consumed, the system will try to generate a document with following number in the sequence but an error will be raised because that number belongs to an expired CAF, althought the user had already uploaded a new CAF.
To fix this, whenever the system looks for the highest number to set to a document, it previously check if that number is between the folio numbers of a valid CAF file.

### Chilean electronic document sequence management

* Added `_get_last_sequence` method to `account_move.py` to ensure that the folio number used for Chilean electronic documents (DTE) is valid and corresponds to an available CAF. If no CAF is available for the current folio, the sequence is reset using the document type's prefix and starting number.

### Certificate model validation

* Made `subject_serial_number` a required field in the `Certificate` model, enforcing that every certificate has a valid owner document and improving data integrity. We made this change to prevent the field being empty after loading the certificate in Odoo, since it is required by the SII to validate invoices.

Forward-Port-Of: odoo/enterprise#92208

**Steps to reproduce:**
* Install and activate the **Uruguayan Localization** for the company.
* Create a contact located in Uruguay.
* Create an invoice for this customer and set **Document Type = 111 (e-Invoice)**.
* From the invoice's gear icon, create a **Debit Note**.

**Observed behavior:**
* The debit note is automatically assigned **Document Type 111 (e-Invoice)**, even though it should use **113 (e-Invoice Debit Note)**.
* Attempting to change the document type manually only shows 113 as an option, confirming the debit note should not have been set to 111.

**Cause:**
* `_compute_l10n_latam_document_type()` applies a rule that assigns Document Type **111** to all Uruguay electronic invoices with RUT identification.
* This logic does **not** check whether the move is a **debit note** (`m.debit_origin_id`), and therefore incorrectly overrides the expected debit note document type.
* The override prevents the correct selection (internal_type == *debit_note*) from being applied.

**Fix:**
* Add a condition in the automatic e-Invoice assignment logic.
* Debit notes now bypass the e-Invoice assignment and fall through to the parent method, which correctly assigns **Document Type 113**.

opw-5154599

Forward-Port-Of: odoo/enterprise#100938