feat(resolvers): Consider changing IPNetResolver to not return an error for empty strings

[erezrokah]

Currently the IPNetResolver returns an error for empty strings. The GCP providers ignore those in specific cases, see https://github.com/cloudquery/cq-provider-gcp/blob/49238085984bc25468ced7484761a3ceb1b7a99e/client/error.go#L59
and https://github.com/cloudquery/cq-provider-gcp/blob/8db6d1e043aec6b17f1f30afc3a0cb551595e34e/resources/services/kubernetes/clusters.go#L145

Ignoring empty strings could be a good default for other providers too, so we should consider it.

The relevant code to update is here

cq-provider-sdk/provider/schema/resolvers.go

Line 177 in 65c7c58

func IPNetResolver(path string) ColumnResolver {

We should first see if other providers experience the same issue as the GCP one

[bbernays]

In Azure, some resources are able to return an empty string as a valid response:
cloudquery/cq-provider-azure@3604559