This Commit contains the following:
* Graceful shutdowns.
* Handling all incoming SSE events for reorgs, finalizations, and head.
The structure of the `BeaconClient` has drastically changed and generics are used.
This concludes all the code needed to connect to the DB and beacon node. We will no longer reference the lighthouse client because this application should work interchangeably with any beacon node.
I have also standardized logging.
