Amcrest

Fix bug in async_vendor_information use of pretty parsing

The vendor_information system property was missed in adding pretty parsing to the system properties for 1.9.0. Add parsing for this property.

Breaking changes
* Drop support for Python 3.6.

New features
* Add new async APIs.

Minor fixes
* Change all system properties, such as hardware_version, to be parsed
out.
* Fix the audio enabled to correctly return the value for the given
channel. This is equivelant to the video fix added in 1.8.1.
* Handle errors fetching the record mode more gracefully.
* Fix the move left/right PTZ commands to take speed as "horizontal".
* Change PTZ commands to return bool rather than str with "ok".

New features
* Add privacy mode control

Bug fixes:
* Fix software_information not returning correct version
* Change is_video_enabled to report only main stream

Breaking changes
==

* Python 2 no longer supported, Python 3.6 is the minimum required version
* PTZ commands (e.g. `zoom_in`, `move_left`) require boolean value for `start` parameter, rather than `"start"` and `"stop"` strings for the `action` parameter

New features
==

* Smart motion detection events added as `is_human_detected` and `is_vehicle_detected` properties.
* Added methods to query separate channels to allow using multiple cameras on NVRs.
* New position_abs PTZ function to allow for absolute angular positioning.
* New function to override ONVIF login checking for admin-only.
* Type annotations added to allow for type checking.

the function event_actions now return (event name, payload)