Split Beta Nodes

[mdproctor]

Currently, BetaNodes implement both tupleSink and ObjectSink to allow them to receive from both sides. This also means that within that node, many operations need a left or a right prefix to indicate the side of the operation.

This code splits the Beta's into two. The right side enters its own class and is added as an adapter delegate property to the beta node. This way, all nodes only have a single parent, and we don't have to have left or right prefixes. I have tried to remove many (but not all) of those prefixes.

Note the code changes the meaning of RightInputAdapterNode. This adapter class is now called RightInputAdapterNode, to mirror the existing LeftInputAdapterNode. What was previously the subnetwork adapter class, called RightInputAdapterNode, has been named more literally after what it actually does, TupleToObjectNode.

It will also make it make future work for different right input strategies to be more easily implemented.

The work should not have any behaviour changes or impact performance in any way.