Changes to Undo a bank-match

added the optional property message to the response with the 200 status

added the optional property error_code to the response with the 400 status

added the optional property error_reason to the response with the 400 status

added the new optional header request parameter Idempotency-Key

added the new optional request property match_group_id

the request property financial_transaction_id became nullable

the request property financial_transaction_id became optional