AWS CodeArtifact (codeartifact) implementation for FakeCloud.
restJson1 control plane for CodeArtifact: domains, repositories (with
upstreams and external connections), package groups, packages and their
versions/assets/dependencies, resource permission policies, authorization
tokens, and resource tagging. Requests are routed by HTTP method + @http
URI path; list/query parameters are read from the raw query string so
repeated multi-value keys survive. Everything is real, persisted,
account-partitioned CRUD -- a PublishPackageVersion actually stores the
asset bytes so a later GetPackageVersionAsset returns them, and a
GetAuthorizationToken mints a synthetic bearer token with an expiration.