Generic Stream support for OOP languages

[mamaso]

Other issues related to Node streaming, read these for some context:
#1361
#660

We need to provide a generic stream abstraction in the RPC layer, which can provide stream inputs to various language workers (node, C#, Java, python, etc).

Need to investigate how streaming functionality may differ across languages - a concrete implementation for node may be the first priority, but we want to create that with other language in mind.

We need to consider how to handle streams as both a top level binding input (i.e. bind to the bytes in my blob), and a property in a property bag object (body property of an http message accessed as a stream).

[mamaso]

@vjrantal

[vjrantal]

Here is one idea about what a Node.js function with input and output streams could potentially look like https://gist.github.com/vjrantal/28b7521a4b22644c357145b7070c9986.