Changes to Get Dispute

the response property actions/subscription became nullable for the status 200

the response property dispute/closed_at became nullable for the status 200

the response property dispute/gateway_substatus became nullable for the status 200

the response property dispute/gateway_version became nullable for the status 200

the response property dispute/invoice/country_code became nullable for the status 200

the response property dispute/invoice_flipped_at became nullable for the status 200

the response property dispute/invoice_status_before became nullable for the status 200

the response property dispute/payment_id became nullable for the status 200

the response property dispute/payment_method became nullable for the status 200

the response property dispute/payment_method_id became nullable for the status 200

the response property dispute/responded_at became nullable for the status 200

endpoint added