Original PR description

#### [IMP] l10n_lv: add tax report attachment tags

Add tags for the tax report attachments added in the related
enterprise PR and tag all existing taxes. They determine the transaction type.

It also adds the special tag `Rep` that is irrelevant for the transaction type.
From a base amount line tagged with `Rep` we only put 40% of the amount
for the attachments.

#### [IMP] l10n_lv: add a car and a representation purchase tax

This commit adds 2 new taxes
- "car tax": 50% of the VAT is deductible
- "representation tax": 40% of the VAT is deductible

#### references
task-4251184

Forward-Port-Of: odoo/odoo#212698

Original PR description

Problem:
In the Spanish VAT books, taxes with negative component (like 21% EU G) always show their amounts as zero.

Steps to reproduce:
1. Install the l10n_es_reports module and select the Spanish company
2. Create a vendor bill with a vendor from another EU country and add a product
3. Make sure the tax applied to the product has a negative component (like 21% EU G)
4. Confirm the bill
5. Go to Accounting > Reporting > Tax Return
6. Generate the VAT books from the action menu and check the tax amounts
7. Notice how the tax amount is zero, even though the tax was applied to the bill

Cause:
When calculating the tax amounts, the negative component cancels out the positive component, leading to the amount always showing as zero in the VAT books.

opw-6169766

Forward-Port-Of: odoo/enterprise#123738