Route container registry requests

We will need to route HTTP requests to registry (e.g. registry.gitlab.com) to the correct cell's registry based on

• Bearer token
• Path
• Username

Refer to https://docs.gitlab.com/ee/architecture/blueprints/cells/impacted_features/container-registry.html, https://docs.gitlab.com/ee/user/packages/container_registry/authenticate_with_container_registry.html

/cc @jdrpereira @adie.po @sxuereb @ayufan