Previously, we would filter containers and images by name, which could be fail if the app was renamed or no longer was tagged "correctly" due to a rebuild. Now, we filter by label, ensuring an app is completely cleaned up on deletion.
Also:
- Move docker image cleanup from apps plugin to builder plugin: This isn't where it belongs - images should be cleaned up in a builder plugin (or the builders plugin) and not in the apps plugin, which has nothing to do with docker images anyways.
- Remove the code from the scheduler plugin, as that will only do anything if the scheduler is enabled for the app.
- Bypass image removal if there are no images to remove
- Always delete app containers: The herokuish builder creates intermediate build containers - something that should be refactored - and ideally this gets run in that builder plugin, but keeping the logic here ensures we don't have code duplication. This is otherwise safe as it will be a no-op if there are no containers to clean up.
This ensures the value is correct, where previously it was computed based on a file - and therefore did not distinguish between git:from-archive and git:from-image.
Closes#4464
0.22.0 changed allowed values for app names, making it more difficult for users to fix their app names - you need to either downgrade+rename or recreate the app. The `apps:rename` command can now rename these old applications to the new standard.
Also drop some app name verification from internal commands. Duplicate verification doesn't help much, and though it isn't excessively slow, it does prevent us from running commands against old apps that exist.
Refs #4267
