Chunked transfer encoding support

[ptrdom]

Currently this library does not provide a way to produce a response with HttpEntity.Chunked, which requires a Source[ByteString, Any].
Implementation needs these steps:

1. New sbt module and a new published artifact, which depends on zio-streams.
2. ZStream to Source conversions. Two ways to approach this.
   • Depends on a third-party library, for example https://github.com/zio/interop-reactive-streams. It is very light on dependencies, so seems like a good choice.
   • Implement custom conversion with the PR.