As a user, I want to view and search images by layer.
Given an image manifest, I want to see the details of the image layers. This info should include the sha256 and size (and other details pulp stores?). Searching for images by layer sha256 necessary when trying to find all images that contain a layer with an issue (such as a CVE).
The search UI would likely be presented through the "docker tags" page at this time.