The tax_exigible field of account.move.line made it impossible to mix 'on_payment' and 'on_invoice' taxes on the same invoice line, as the base line couldn't be be tax exigible and non-tax exigible at the same time. However, this use case is needed by some countries in order to implement withholding taxes.
To solve that, we totally remove the tax_exigible field from account.move.line and instead compute it on the fly with a domain (also passed to the query_get for SQL queries). An 'always_tax_exigible' stored computed field is also added on account.move, in order to still allow (like before) putting cash basis taxes on a miscellaneous operation without any payable/receivable line and still see it become exigible without needing any payment.
[IMP] account: improve cash basis traceability
A smart button is now available on invoices generating cash basis entries, so see them all at once. The move originally creating cash basis entries is also shown as a field on them.
Task: 2457374
Part-of: odoo/odoo#74138
oco-odoo
d8c4332c8d