In the Kubernetes API client, we should be able to generate queries like
?labelSelector=environment+in+%28production%2Cqa%29%2Ctier+in+%28frontend%29
(from https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#list-and-watch-filtering).
When the generated URIs URL-encode the plus signs, the API server rejects them.
With this change, (newConfig :: IO KubernetesClientConfig) now sets
the default configQueryExtraUnreserved setting to "+". Requests
generated with this config object will avoid URI encoding "+" all
querystring params.
