Add threading to socket check

[dsgnr]

Adds threading to query_ipv4 method. Uses default worker value (CPU count). This will improve performance where there are more than one port that does not response, thus reaching the timeout limit.

Before:

  >>> import os;os.cpu_count()
  12
  >>> from timeit import timeit
  >>> r = 'import requests; requests.post("http://localhost:8000/api/query", json={"host": "google.com", "ports": [21, 22, 23, 25, 53, 80, 110, 443, 465, 8080, 8443, 9090]}).json()'
  >>> timeit(r, number=1)
  10.265458297042642

After:

  >>> import os;os.cpu_count()
  12
  >>> from timeit import timeit
  >>> r = 'import requests; requests.post("http://localhost:8000/api/query", json={"host": "google.com", "ports": [21, 22, 23, 25, 53, 80, 110, 443, 465, 8080, 8443, 9090]}).json()'
  >>> timeit(r, number=1)
  1.041649337974377