Support <resource>/<name> form as a query

[tksm]

Fixes #159

This PR supports a Kubernetes resource as a query in the form <resource>/<name>. As discussed in #206, this PR supports it as a query rather than a flag.

This feature will be useful when we want to distinguish pods created by multiple deployments whose names are partly the same.

$ kubectl get deploy -n kube-system | grep cert-manager
cert-manager              1/1     1            1           63d
cert-manager-cainjector   1/1     1            1           63d
cert-manager-webhook      1/1     1            1           63d

# It is not easy to select only pods created by `deployment/cert-manager` with a regular expression
$ stern -n kube-system --tail 0 cert-manager
+ cert-manager-webhook-6c587d5b6f-x26dr › cert-manager
+ cert-manager-7ff5799cff-7gjv5 › cert-manager
+ cert-manager-cainjector-6b4cf6bdf9-rxpcn › cert-manager

# The <resource>/<name> form allows users to select only pods created by `deployment/cert-manager`.
$ stern -n kube-system --tail 0 deployment/cert-manager
+ cert-manager-7ff5799cff-7gjv5 › cert-manager

Supported Kubernetes resources are the same as kubectl logs, which are pod, replicationcontroller, service, daemonset, deployment, replicaset, statefulset and job.

I will implement a dynamic completion for this feature after this PR is merged.

[superbrothers]

Thanks for the change! I will review it soon.

[tksm]

Thank you for the review! I created PR #209, adding a dynamic completion for this feature.