[FIX] base_vat: belgian vat number correct display
[FIX] base_vat: belgian vat number correct display

Odoo Accept the following mask for vat encoding :
BE0477472701
BE.0.477.472.701
BE.477.472.701
BE477.472.701
BE477472701

But, in certain cases we have to add the zero to be compliance (i.e. belgian official reports...). -> http://www.tvaintracommunautaire.eu/belgique.html

This commit make use of the compact method defined in stdnum.be.vat (which is used by vatnumber in order to validate the vat). The compact method return a 10 digits vat number starting with a 0 which is compliant with the official reports.

closes odoo/odoo#28523
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo