Create a `WorkerChain` class

[mathemaphysics]

Just at the Worker class level we can create a series of worker that process data in steps just like a program. This is a pipeline with an adjustable width. It's workers run just like a program with the exception that their data can be relocated anywhere and consumed by another Worker or series of workers. The output of the previous Worker is the input to the next Worker in the chain.

The natural generalization of this WorkerChain class is a WorkerGraph. A single Worker can process data and send the results to any one of multiple other kinds of workers, depending on what was discovered in the message. This is the eventual goal of the concept. Such graphs of Workers are natural granular generalizations of a computer program with the exception that operations are always transferable to another worker without shared memory as a requirement.