Multi-threaded features needed for Server

[alexeypetrushin]

About being able to send and receive messages with id with `channels` \- 
actually seems like it's possible [full 
snippet](https://gist.github.com/al6x/aea6d6a854904c39a4e1830f79372f2e)
    
    
    # Answering Service
      let answering_service_id = 1
      proc answering_service(): void =
        listen((question) => fmt"answer to {question}")
      answering_service.run_in_thread(answering_service_id)
      
      # Some Worker
      proc some_worker(): void =
        for i in 1..5:
          echo answering_service_id.call(fmt"question {i}")
        
        # Askind in batch
        echo call(@[
          (answering_service_id, "question 6"),
          (answering_service_id, "question 7")
        ])
      some_worker.run_in_thread(2)
    
    
    Run