[IMP] l10n_it: Internal Reverse Charge

[lordkrandel]

Add support for Internal Reverse Charge invoicing flows in Italy.

• Add 0% sale taxes and purchase taxes targeting VJ grids in l10n_it for every Tax Exemption Reason involved (Scrap, Gold...)
• Add a Fiscal Position (equivalent to the Belgian "CoContractant" one) mapping the sale tax and purchase taxes to their Reverse Charge corresponding taxes. Those fiscal positions all have a different law-required note (with the law reference) that has to be printed on the PDF invoice through Odoo standard mechanisms.
• The way we compare the invoice features and each document type requirements has been revised and expanded for the tax_tags sets case. Now it should also avoid comparisons after the first failure, instead of doing all the comparison anyway.
• Imported vendor bills that have TD16, TD17, TD18 now have their 0% reverse charge sale taxes converted to their purchase 22% VAT reverse charge corresponding tax impacting VJ tax grids, following this mapping:

  Sale tax examption reason -> VJ grid targeted by purchase tax
    N3.2:  VJ3
    N3.3:  VJ1
    N6.1:  VJ6
    N6.2:  VJ7
    N6.3:  VJ12
    N6.4:  VJ13
    N6.5:  VJ14
    N6.6:  VJ15
    N6.7:  VJ16
    N6.8:  VJ17

• Vendor bills that have taxes targeting grids VJ6, VJ7, VJ8, VJ12, VJ13, VJ14, VJ15, VJ16, VJ17 are exported as Tax Integrations XMLs to be sent to the Tax Agency with the document type TD16
• Vendor bills that have taxes targeting grid VJ3 are exported as Tax Integrations XMLs to be sent to the Tax Agency with the document type TD17
• Vendor bills that have taxes targeting grid VJ9 are exported as Tax Integrations XMLs to be sent to the Tax Agency with the document type TD18

Documentation PR: odoo/documentation#7789

Link: https://www.odoo.com/web#model=project.task&id=3724926 task-3724926

[robodoo]

.

[lordkrandel]

We do not support import of customer invoices?

No, not until we merge this PR that I still have to test and do the fw-ports.

[jco-odoo]

@robodoo r+ rebase-ff

[robodoo]

Merge method set to rebase and fast-forward.

[robodoo]

@lordkrandel @jco-odoo staging failed: ci/l10n on 90d4b9d9df520b4497e9bc98294996605a732ad9 (view more at https://runbot.odoo.com/runbot/build/59511942)

[lordkrandel]

@robodoo r+

[robodoo]

I'm sorry, @lordkrandel: you can't review+.

[lordkrandel]

I'm sorry, @lordkrandel: you can't review+.

Oh, well, I tried

[jco-odoo]

@robodoo r+