Implement payload de/fragmentation

[arnauorriols]

Description

Specs define the process by which Streams must fragment and defragment payloads bigger than the UNIFORM PAYLOAD LENGTH field of the HDF

Motivation

It's in the specs

Requirements

1. I can send messages with payloads bigger than 32KiB without having to split them into smaller messages
2. I can receive messages bigger than 32KiB without having to join smaller messages

Are you planning to do it yourself in a pull request?

Yes