Use tasks in analytic model tester tool

[VargBurz]

this PR updates analytic_model_tester.py tool: get learning and detection info using tasks, same as analytics gets from server.

Motivation:

We want to test the whole analytics process, not only models

Changes:

• Use AnalyticUnitManager instance instead of Detector
• ModelData class:
  • new get_task method: create learning or detection task
  • new get_formated_segments, get_positive_segments, get_negative_segments methods to simplify segments control
    • use asyncio: main() is async function now
    • main(): send learning and detection tasks to AnalyticUnitManager and await its results