Moved header constants for streaming into CMF
Simplifying the API for end users based on internal reviews.
Cleaned up java doc comments and removedIStreamingProgressUpdater class as it was no longer needed.
IsLast flag no longer needed as it will be replaced by an object to indicate to the event bus that the last event was received and the stream can be closed.
Added in type to be used for when events need to be deserialized.