CHW-4816 DockerManifestPathInvalid

docker manifest push path is malformed; expected {name}/manifests/{reference}

Default message: docker manifest push path is malformed; expected {name}/manifests/{reference}
HTTP status: 400 (client)

Problem. Docker manifest PUT arrived with a malformed path. Cause. Expected {name}/manifests/{reference}; the reference segment was missing or manifests was first. Fix. Push against the canonical .../manifests/{tag-or-digest} URL. HTTP 400.