Description:

Added a sensor platform to retrieve data from the qBittorrent API.

Documentation PR home-assistant/home-assistant.io#7597

Example entry for configuration.yaml (if applicable):

sensor:
  - platform: qbittorrent
    url: "http://192.168.0.xx:8080"
    username: <username>
    password: <password>

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New or updated dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.
• New files were added to .coveragerc.