feat: add support for virtual can

[ardrabczyk]

I'm going to use it like that in an algorithm for auto-detecting CAN speed (I also need listen-only mode for that #174):

canInfo, err := d.Info()
if err != nil {
        return err
}

if canInfo.Type == candevice.VcanLinkType {
        log.Println("Type is vcan, cancel auto-detecting CAN speed")
        return nil
}

SetBitrate() and others don't have to changed, they will return netlink receive: operation not supported errors. Receive() and TransmitFrame() will continue working without any changes.

There are no tests, I thought I could add them to pkg/candevice/device_integration_test.go but nothing there uses vcan0 at this moment.

[Edholm]

Please have a look at the failing CI

[ardrabczyk]

yeah I know that tests fail but IMO it should be fixed elsewhere because all builds fail since Sep 4 https://github.com/einride/can-go/actions and by the time when I pushed this PR they were already failing.

[Edholm]

Yeah I noticed after I wrote. I will take a look. I suspect it is due to the Go version having been bumped to 1.21 :)

[Edholm]

Should be fixed now. You can rebase on master :)