Delete images by name instead of ID

[MRayermannMSFT]

While I understand the error, it'd be great if there was a feature that helped me determine what child images were causing this error:

[philliphoff]

That's a good idea. I could see scanning for and adding a list to the error message itself, though that could get unwieldy. Perhaps an option to group images by base image?

[bwateratmsft]

@MRayermannMSFT @philliphoff I've been working on something I think you're gonna like. Here's a couple screenshots that I think convey the concept:

[bwateratmsft]

Changed the issue title. The fix we made will delete images by name instead of by ID. There are a couple of implications of this:

1. If the image is in use by a container, it will be untagged, but "deletion" succeeds. Later, if images are pruned, the now-untagged image will be deleted (no more 409 Conflict errors).
2. If the image is in use by child images, it will be untagged, but "deletion" succeeds. Later, if the child image is removed, the now-untagged image will be deleted (no more 409 Conflict errors).
3. If the image is not in use by containers or child images, but there are multiple tags for the image, it will be untagged. The other tags will remain. We have had user feedback that the current deletion--which removes all tags--is awkward.
4. When the last tag is removed from an image, and there are no containers or child images using it, it will be truly removed.