add functional fields identifier_type and vat_code

aeat.py

@@ -718,6 +718,19 @@ class SIIReportLine(ModelSQL, ModelView):
     company = fields.Many2One(
         'company.company', 'Company', required=True, select=True)
 
+    vat_code = fields.Function(fields.Char('VAT Code'), 'get_vat_code')
+    identifier_type = fields.Function(
+        fields.Selection(PARTY_IDENTIFIER_TYPE,
+        'Identifier Type'), 'get_identifier_type')
+
+    def get_vat_code(self, name):
+        return self.invoice.party.vat_code
+
+    def get_identifier_type(self, name):
+        return self.invoice.party.identifier_type
+
+
+
     @staticmethod
     def default_company():
         return Transaction().context.get('company')

view/sii_report_lines_list.xml

@@ -1,9 +1,11 @@
 <?xml version="1.0"?>
 <!-- The COPYRIGHT file at the top level of this repository contains the full
      copyright notices and license terms. -->
-<tree string="AEAT SII Issued Lines">
+<tree string="AEAT SII Issued Lines" editable="bottom">
     <field name="report"/>
     <field name="invoice"/>
+    <field name="vat_code"/>
+    <field name="identifier_type"/>
     <field name="state"/>
     <field name="communication_code"/>
     <field name="communication_msg"/>