Sweep emitted events

During the state transition event connector puts an event in an in-memory queue (and database) which is then picked up by the background process to emit the event to SQS. If the process is interrupted there is a database record which indicates that the event has been put in an in-memory queue, but not yet emitted to the SQS. <br>This task retrieves all the records that haven't been fully processed, for each event it invokes the backfill process and marks the event as processed.<br>The default age of the non-emitted event is at least 30 minutes. This value can be controlled with NOT_EMITTED_EVENT_MAX_AGE_IN_SECONDS environment variable.