Added warning msg for kubectl get

- added warning description regarding terminated objects to `get` long help message
  - added printing of warning message in case of `get pods` if there are hidden pods
Fixes #22986

pkg/kubectl/cmd/cmd_test.go

@@ -165,6 +165,10 @@ func (t *testPrinter) HandledResources() []string {
 	return []string{}
 }
 
+func (t *testPrinter) FinishPrint(output io.Writer, res string) error {
+	return nil
+}
+
 type testDescriber struct {
 	Name, Namespace string
 	Settings        kubectl.DescriberSettings