Rename message_id to time_id. Use _id for sequential message index given by producer and time_id for message based on arrival time.

Fix stream_delete functionality. Now stream metadata, auto_incrementing_id and list of streams are cleaned up.

Add PipelineStepId in the list of group delays. Fix representation of pipeline topology. Add new variable in the proto.

This reverts commit e4f9d3e4.

Adds rdkafka dependency, rdkafka client,
and notification for file close event

Adds rdkafka dependency, rdkafka client,
and notification for file close event