Move ssh and kube client from dhctl
Move
https://github.com/deckhouse/deckhouse/tree/b518860d6d4cea2a61dde22708eb284d3a0b7c37/dhctl/pkg/system/node
and
https://github.com/deckhouse/deckhouse/blob/b518860d6d4cea2a61dde22708eb284d3a0b7c37/dhctl/pkg/kubernetes/kube.go
and
https://github.com/deckhouse/deckhouse/blob/b518860d6d4cea2a61dde22708eb284d3a0b7c37/dhctl/pkg/kubernetes/client/client.go
to standalone library with huge refactoring, fixes and tests. Please see README.md in root of repo for additional information.