Add chunk bulk upload API

[tmm360]

Summary

Current http and websocket upload APIs are heavily suboptimized. A better API to improve upload speed is necessary.

Motivation

Current POST /chunks API and websocket protocol work in the same way, sending one chunk at time, and waiting ack from node.
All the time the network is always waiting for something, or to receive new chunk data, or confirmation that data has been received. The network line is always empty of data.

Instead, to have a continuous stream of chunks is a really better solution.

Implementation

I've implemented an alternative rest API into an experimental reverse proxy project that I've called "BeeTurbo". It is putted directly in front of bee.

api implementation: https://github.com/Etherna/bee-turbo/blob/3516cf9f0b67af3ae58308d5f7433048fdbff5aa/src/BeeTurbo/Handlers/ChunksBulkUploadHandler.cs

Basically, it receives a set of chunks with a single POST request. Payload is composed as continuous list of chunks, where each one is described as:

• uint16 with chunk's size in byte
• chunk's payload, of the given size
• swarm hash, used only to check chunk's integrity

Drawbacks

The new api is not retro-compatible, a new endpoint has to be introduced