Added VAT to system invoices rows when there is an AMEX payment
NEUROP-970
- Changed system invoice no. if is a test invoice
- Changed tables structure to admit test/prod mode, total VAT amount (system_invoice), VAT percentage and vat amount (system_invoice_row)
- Added parameter to define the VAT percentage (now at 25%)
- Changed system invoice tables to show all data and changed also model details view