Platform service links

Often teams may use a registry as some form of a centralized hub to their ML platform, which may include additional external services (e.g. feature store) that they record prometheus metrics for. Opsml should allow users to specify a configuration file where they can specify these external services, so that opsml can display their links and health status and traffic from an internal dashboard. This is in-line with the goal of having opsml be a unified experience for developers and engineers