TryRefreshAsync does not handle the case when initial configuration load has failed

[abhilasharora]

No description provided.

[abhilasharora]

I'm thinking about updating the code to allow loading of initial configuration even when there are no refresh registrations. This will be helpful for scenarios where users don't intend to refresh any value, but still use the RefreshAsync method to try to recover from initial load failures. It basically allows them to catch failures during initial load, and then use refresh to trigger a retry. I can use the default 30 second refresh cache expiration here.