Incoming messages pipeline

When handling received messages, everything starts with Rebus having received one single message from its configured ITransport.

When it has a message, it will add the message to an incoming step context and invoke its pipeline of incoming message steps.

Each incoming message step then has one function, e.g. one of the steps (DeserializeIncomingMessageStep) will deserialize the message and store the result in the context, making it available for the subsequent steps to use.

In a similar way, outgoing messages will be passed through an outgoing messages pipeline.