Move uri field to the base DockerImage type

What does this MR do and why?

Move uri field to the Types::GoogleCloud::ArtifactRegistry::DockerImageType to allow Copy image path on the list page.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

How to set up and validate locally

1. Required setup for Google Cloud is described here

2. Visit http://gdk.test:3000/-/graphql-explorer and create the GraphQL request

query getGarArtifactsFromProject {
  project(fullPath: "gitlab-org/gitlab-test") {
    id
    googleCloudArtifactRegistryRepository {
      artifacts {
        nodes {
          ... on GoogleCloudArtifactRegistryDockerImage {
            uri
          }
        }
      }
    }
  }
}