feature(wsgi): pre-fork worker model module

[pcanto-hopeit]

Significant performance improvements by executing hopeit_server using gunicorn in a multicore environment.

• hopeit_server command have new --workers and --worker-class params:

  • Setting --workers=2 allows to start hopeit.engine with 2 engine workers to respond
    requests from the same port. This feature was implemented with gunicorn.
    Default value is --workers=1. Max number of workers is (cpu_count * 2) + 1.
  • To set --worker-class there are two possible options: GunicornWebWorker, GunicornUVLoopWebWorker.
    Refer to aiohttp <https://docs.aiohttp.org/en/stable/deployment.html#start-gunicorn>_
    docs for more details.
    Default value is --worker-class=GunicornWebWorker