FEATURE REQUEST: Ability to control response stream #362

New Issue Checklist

• I have tried with the latest version of OHHTTPStubs
• I have read the README
• I have read the Using the right Swift Version of OHHTTPStubs for your project section
• I have searched in the existing issues
• I have read the OHHTTPStubs wiki to see if there wasn't a detailed page talking about my issue

Environment

• version of OHHTTPStubs: 9.1.0
• integration method you are using:
  • Cocoapods
  • Carthage
  • submodule
  • other Swift Package Manager
• version of the tool you use: Uhh....package tools version 5.6

Issue Description

I am attempting to use this to test a Server-Sent Events implementation. That particular protocol likes to send data in chunks of varying sizes as it streams, example:

id: 1
data: This

data:  is

data:  a

data:  sentence

data: .

OHHTTPStubs at the moment doesn't seem to expose a way to send partial responses back as part of the stream. Specifically, what I need is the URLSessionDataDelegate to have its urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) method called with each sent event.

An ideal solution in my mind would be to allow me to pass an array of Data to the response and have it work out the rest, but honestly I'd be up for anything that worked.