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/index.md

@@ -555,6 +555,21 @@ cameras:
       user: admin
       # Optional: password for login.
       password: admin
+      # Optional: PTZ camera object autotracking. Keeps a moving object in
+      # the center of the frame by automatically moving the PTZ camera.
+      autotracking:
+        # Optional: enable/disable object autotracking. (default: shown below)
+        enabled: False
+        # Optional: list of objects to track from labelmap.txt (default: shown below)
+        track:
+          - person
+        # Required: Begin automatically tracking an object when it enters any of the listed zones.
+        required_zones:
+          - zone_name
+        # Required: Name of ONVIF camera preset to return to when tracking is over.
+        return_preset: preset_name
+        # Optional: Seconds to delay before returning to preset. (default: shown below)
+        timeout: 10
 
     # Optional: Configuration for how to sort the cameras in the Birdseye view.
     birdseye: