Authnet: Parse card_type from response

[dingels35]

When creating a new ActiveMerchant::Billing::Response, the AuthorizeNetGateway does not populate params with all of the data that is returned in Authorize.net's XML response.

One of the missing fields is card_type. This PR follows the convention in AuthorizeNetGateway to add that value.

% rake test:units
Finished in 9.844451 seconds.
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4056 tests, 69070 assertions, 0 failures, 0 errors, 0 pendings, 2 omissions, 0 notifications
100% passed
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412.01 tests/s, 7016.14 assertions/s

% rake test:remote TEST=test/remote/gateways/remote_authorize_net_test.rb
Finished in 61.416603 seconds.
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69 tests, 238 assertions, 0 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications
100% passed
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1.12 tests/s, 3.88 assertions/s

[dingels35]

Included in #3224