List containers by App

[iwilltry42]

• [ ] acorn containers -h shows acorn container [flags] [APP_NAME...], where passing in an actual app name would result in

  $ acorn containers little-water
  Error: containers.api.acorn.io "little-water" not found
  

  • I guess it should be acorn container [flags] [CONTAINER_NAME...]
• [ ] It would still be nice to have a way to filter the acorn containers list output by app name, e.g. via a flag acorn containers --app APP-NAME or by having some --filter options, similar to the docker filters