This convenience was necessary to be used for golang library functions like io.Copy and io.Pipe
where we shouldn't be writing proxies and alternatives returning *probe.Error
This change also brings more changes across code base for clear separation regarding where an error
interface should be passed encapsulating *probe.Error and where it should be used as is.
In many cases fmt.Errorf is good enough, but since
error is an interface, you can use arbitrary data
structures as error values, to allow callers to
inspect the details of the error.
karthic rao