external "editor" functionality

[ghostsquad]

Allow things to be edited natively using their favorite editor.

References:

https://github.com/kubernetes/kubectl/tree/master/pkg/cmd/util/editor

https://samrapdev.com/capturing-sensitive-input-with-editor-in-golang-from-the-cli/

https://github.com/derailed/k9s/blob/master/internal/view/exec.go?ts=4