WIP: Fix ironbank/registry1 hash mismatch

Previously, the ironbank frontend was showing the image id not the digest which is what Harbor shows. The image id isn't stable and should have never been shown in the UI.

Problem: it appears that the digest is unpredictable until you've pushed to the remote registry. And the digest id is not stable across save/load. Those links are for Docker, but show that these issues are inherent in Docker registries and the Docker image tar format. The Docker image tar format does not actually store the same JSON file that the manifest id is derived from, making this impossible.

I could change this MR to retrieve the digest ID after pushing to the registry so that the frontend shows the hash that matches Harbor. But it is impossible to make the digest of the downloadable tar match one from the registry.

closes #16