Connection IDs are missing from error messages

The error messages that MaxScale logs whenever a connection to a server is lost does not log the connection ID of the backend connection nor the session ID in MaxScale. This makes it very hard to figure out which errors on the backend server relate to this session in MaxScale. The backend connection ID information is available even now but it's only in the log_info output that's too verbose to be kept on permanently. The session ID is also available in all the MaxScale log messages but if the driver does not print the connection ID, it will be difficult to map client errors to the MaxScale session.

The errors generated by the protocol modules for all fatal errors should thus contain the MaxScale session ID and the connection ID on the backend server if the authentication has reached that point.