[FIX] *: avoid direct references to countries

Ensure the code works fine even if countries are deleted.

Also consider "re"-created countries after deletion, by only considering
the country code, not the data reference.

This should reduce support requests related to deleted countries, and
ease the resolution of such problems by the users themselves.

TASK ID - 2368842

closes odoo/odoo#57837

Related: odoo/enterprise#13275
Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>