kube refine for backup

Define the required information in `$env.KUBERNETES_REFINE`,
`kube refine` will collect information according to its definition

Definitions in `status` and `cluster_status` are runtime information and will not be collected. They are used in the `kg` command to display status

A new module, `refine.nu`, declaratively extracts data from complex structures.

`container-list` additionally displays the cmd field of the image

rename `kcconf` to `kccc` (kubectl change context clone)

modules/docker/docker.nu

@@ -47,6 +47,7 @@ export def container-list [
         let img = ^$cli ...($n | with-flag -n) inspect $image
             | from json
             | get 0
+        let imgCmd = $img.Config.Cmd?
         let imgEnv = $img.Config.Env?
             | reduce -f {} {|i, a|
                 let x = $i | split row '='
@@ -71,6 +72,7 @@ export def container-list [
             env: $imgEnv
             mounts: $m
             entrypoint: $r.Path?
+            cmd: $imgCmd
             args: $r.Args
         }
     }