FIX: subscriptions use vat instead email

FIX Issue #26 (closed)

https://trello.com/c/LGRZ3Bli/159-use-vat-to-identify-existing-respartner-instead-of-email

Change list:

• Inherit method of cooperator to search by vat instead of email.
• Added method to partner to search by vat.
• Added VAT field required and states to fix control in form view.

TODO

• company_register_number is a field used by cooperator for cooperators companies, we should use vat for companies and persons.
• Create a PR to l10n_es_cooperator, we're still waiting OCA to resolve the PR

energy_communities/models/res_partner.py

@@ -6,3 +6,14 @@ class ResPartner(models.Model):
 
     gender = fields.Selection(selection_add=[("not_binary", "Not binary"),
                                              ("not_share", "I prefer to not share it")])
+
+    def get_cooperator_from_vat(self, vat):
+        if vat:
+            vat = vat.strip()
+        # email could be falsy or be only made of whitespace.
+        if not vat:
+            return self.browse()
+        partner = self.search(
+            [("vat", "ilike", vat)], limit=1
+        )
+        return partner