Allow to send and receive binary files in java11 template

[vane]

Expected Behaviour

Allow to get byte[] data instad of string in request

Current Behaviour

Only string is allowed

Possible Solution

Read body as byte[] and use IRequest getBodyBytes() IResponse setBodyBytes()

Steps to Reproduce (for bugs)

1. Create echo function that sends input back to output
2. Send file with POST request
3. Received file have different size

Context

Your Environment

• Docker version docker version (e.g. Docker 17.0.05 ):
  19.03.8
• Are you using Docker Swarm or Kubernetes (FaaS-netes)?
  Docker Swarm
• Operating System and version (e.g. Linux, Windows, MacOS):
  Linux, MacOS
• Link to your project or a code example to reproduce issue: