Add an SAHC transaction type for processing a sale and creating a token

Currently authorization,create_payment_token is supported but from what I understand of Cybersource API documentation the same request format is required for sale,create_payment_token.

Can we simply extend this with:

const COMMERCE_CYBERSOURCE_SAHC_TRANSACTION_SALE_CREATE_TOKEN = 'sale,create_payment_token';

and

    $form['transaction_type'] = [
      '#type' => 'select',
      '#title' => $this->t('Transaction type'),
      '#default_value' => $this->configuration['transaction_type'],
      '#required' => TRUE,
      '#options' => [
        self::COMMERCE_CYBERSOURCE_SAHC_TRANSACTION_AUTH_CREATE_TOKEN => $this->t('Authorize funds and create payment token'),
        self::COMMERCE_CYBERSOURCE_SAHC_TRANSACTION_SALE_CREATE_TOKEN => $this->t('Capture funds and create payment token'),
      ],
    ];