This update standardizes how the system reads country-specific sections of IBAN bank account numbers. It makes payment-related code easier to maintain and reduces the chance of future mistakes when handling bank data for ISO 20022, UK BACS, and Italian Ri.Ba. payments.

Factoring out a standard method of identifying parts of the IBAN depending on the country, making it easier to read and understand instead of slicing the IBAN with magic numbers

Community PR: odoo/odoo#189288