Changes to Retrieve a billing statement

added the new payer-credits enum value to the groups/items/items/items/payment_method/payment_type response property for the response status 200

added CommerceTotalsResponse-2 to the groups/items/items/items/totals response property allOf list for the response status 200

removed schemas-CommerceTotalsResponse from the groups/items/items/items/totals response property allOf list for the response status 200

added schemas-CommerceTotalsResponse to the groups/items/items/items/totals response property allOf list for the response status 200

removed CommerceTotalsResponse from the groups/items/items/items/totals response property allOf list for the response status 200

added the optional property groups/items/items/items/totals to the response with the 200 status

added the required property totals/base_fee to the response with the 200 status

added the optional property groups/items/items/items/payer/credits_balance to the response with the 200 status

added the optional property payer/credits_balance to the response with the 200 status