Cassandra connection avoid cloning entire message

[rukai]

The connection logic was previously cloning the entire message when it really needed was the stream_id and version fields.
I removed the message clone and changed the connection logic to get the values from:

• stream_id - Sent to the rx task where the original message used to be.
• version - The transform is now responsible for keeping track of the version. Its constant per connection, so we can just set it once from the first message and it will always be the same.

This is a prereq for cassandra error handling improvements.