Add support for returnMethod parameter

The parameter of the underlying library configures
type of request which gateway uses to return
to the origin site.

If not set, POST is used, this parameter can override
the behavior if necessary (for example for scenarios
where some cookies are not sent because of the SameSite
settings).

Consider status "settled" as successful

Add support for transaction reference extraction in OneClickPayment

Manually close the payment if the configuration requested it

Since API v1.9 the underlying library used for requesting CSOB API
doesn't read the closePayment config globally and reads it only
from the $newPayment instance.

Unfortunately there's no way how to tell $newPayment that it should
close and we end up with unclaimed payments.

If the caller configured the omnipay library to close the payment,
this will enforce the closure.

Add support for customerId parameter

Add support for configuring traceLog

Update library for use with CSOB API 1.9

Merge pull request #2 from miroc/master

Update to PHP 8.0

Add missing paymentStatus request to the gateway spec

Add PaymentStatusRequest and support for CardNumberExtension