AuthNet Error Conflicts with Swift Error Definiton

[mdewolfe]

The Authorize.NET definition of Error conflicts with the Error protocol defined In Foundation.

Foundation Error (Found in Swift->Misc):

public protocol Error {
}

// AuthNetSDK->Error.h
@interface Error : NSObject {

	NSString *errorCode;
	NSString *errorText;
}

This has appeared in the past and it seems not enough care has been taken to avoid the naming collisions, see #24

This is a critical conflict since it conflicts with a Foundation protocol.

Using SDK v4.2, Targeting iOS 12, using Swift 5.