Allow overwriting plugin output with command's stdout

[rtim75]

Closes #2617

This allows plugin developers to overwrite standard Plugin command launched successfully: "Command completed successfully:..... with their custom messages.

I have a plugin that finds all ingress hosts and saves them in MacOS clipboard:

plugins:
  copy-ingress-hosts:
    shortCut: h
    confirm: false
    overwriteOutput: true
    description: Copy ingress hosts
    scopes:
      - ingresses
    command: sh
    background: true
    args:
      - -c
      - >-
        kubectl --context $CONTEXT
        get ingress -n $NAMESPACE $NAME
        -o go-template='{{range .spec.rules}}{{.host}},{{end}}' | sed 's/,$//' | pbcopy && echo "Successfully copied hosts"

with overwriteOutput: true when I execute the plugin I receive Successfully copied hosts:

[derailed]

@rtim75 Nice! Thank you for this update!!