* Process to send events to configured sinks
This PR adds a SinkManager to a server which is responsible for managing
managed sinks. Managed sinks subscribe to the event broker and send
events to a sink writer (webhook). When changes to the eventstore are
made the sinkmanager and managed sink are responsible for reloading or
starting a new managed sink.
* periodically check in sink progress to raft
Save progress on the last successfully sent index to raft. This allows a
managed sink to resume close to where it left off in the event of a lost
server or leadership change
dereference eventsink so we can accurately use the watchch
When using a pointer to eventsink struct it was updated immediately and our reload logic would not trigger
