PaymentOptionsBuilder::buildOptions does not filter out payment gateways with mismatching modes

The problem can be seen in #2965800: After update to latest dev, "paymentProfileId' element is invalid" error.

When there is no "owner ID" we assume the user is anonymous. So we try to extract the remote customer profile ID and remote payment ID from the payment method ID. When the user is logged in, the payment method remote ID is only the remote payment profile ID.

We can do a fix in Authorize.net but we should be filtering payment methods.

After

$payment_gateways_with_payment_methods = array_filter($payment_gateways, function ($payment_gateway) {
      /** @var \Drupal\commerce_payment\Entity\PaymentGatewayInterface $payment_gateway */
      return $payment_gateway->getPlugin() instanceof SupportsStoredPaymentMethodsInterface;
    });

We should then filter out payment methods whose payment_gateway_mode do not match the payment gateway's getMode result.

         $payment_methods = $payment_method_storage->loadReusable($customer, $payment_gateway, $billing_countries);

Wouldn't it make more sense to perform the filtering here, in PaymentMethodStorage::loadReusable()? That would also allow it to be performed on the query level.

I'd like to have test coverage here. I think we're missing generic coverage of our payment gateway mode logics.

We should use $payment_gateway->getPlugin()->getMode(). Writing tests and wrapping this up.

Here is fix using proper method and tests that changing the payment gateway's mode does not load the previous payment methods as being reusable.

Fixed!