Add key functions 'SetPtzPreset' and 'GetAiState'

[sracing]

Hi,
First of all - thank you for your great work here! I would like to use cam2mqtt as a module in a Home Automation application (SmarthomeNG, see [https://www.smarthomeng.de/]. What I am missing are the following functions:

• call a specific PTZ Position (Reolink Command "SetPtzPreset")
• get the AI Alarm State (Reolink Command "GetAiState")

Is that something you could consider to add to your code?

Regards - Marcus

[berfenger]

Now with the last changes, when the motion is tracked through ONVIF events (onvif: monitor_events: true), the GetAiState is called periodically to check the AI state and send people and vehicle detection events to MQTT (only if the camera supports so).