Changes to Approve many

added the new tax enum value to the items/line_item_type response property for the response status 200

api tag /billing_new/invoice_line_items added

removed the XXX enum value from the items/currency_code response property for the response status 200

removed the XXX enum value from the items/currency_conversion/anyOf[subschema #1: InvoiceLineItemCurrencyConversion1]/source_currency_code response property for the response status 200

removed the tax_1 enum value from the items/line_item_type response property for the response status 200

removed the tax_2 enum value from the items/line_item_type response property for the response status 200

removed the tax_3 enum value from the items/line_item_type response property for the response status 200

added the required property items/total_amount to the response with the 200 status