Basic PTZ object autotracking functionality (#6913)

* Basic functionality

* Threaded motion estimator

* Revert "Threaded motion estimator"

This reverts commit 3171801607.

* Don't detect motion when ptz is moving

* fix motion logic

* fix mypy error

* Add threaded queue for movement for slower ptzs

* Move queues per camera

* Move autotracker start to app.py

* iou value for tracked object

* mqtt callback

* tracked object should be initially motionless

* only draw thicker box if autotracking is enabled

* Init if enabled when initially disabled in config

* Fix init

* Thread names

* Always use motion estimator

* docs

* clarify fov support

* remove size ratio

* use mp event instead of value for ptz status

* update autotrack at half fps

* fix merge conflict

* fix event type for mypy

* clean up

* Clean up

* remove unused code

* merge conflict fix

* docs: update link to object_detectors page

* Update docs/docs/configuration/autotracking.md

Co-authored-by: Nicolas Mowen <nickmowen213@gmail.com>

* clarify wording

* pass actual instances directly

* default return preset

* fix type

* Error message when onvif init fails

* disable autotracking if onvif init fails

* disable autotracking if onvif init fails

* ptz module

* verify required_zones in config

* update util after dev merge

---------

Co-authored-by: Nicolas Mowen <nickmowen213@gmail.com>

docs/docs/configuration/cameras.md

@@ -66,3 +66,5 @@ cameras:
 ```
 
 then PTZ controls will be available in the cameras WebUI.
+
+An ONVIF-capable camera that supports relative movement within the field of view (FOV) can also be configured to automatically track moving objects and keep them in the center of the frame. For autotracking setup, see the [autotracking](autotracking.md) docs.