Clean up onvif and autotracking (#24559)

* simplify onvif and autotracking code

Removes about 230 lines from the ONVIF controller and autotracker without changing how PTZ moves are calculated. `OnvifController` no longer keeps its own `camera_configs` copy of the camera config, the cached `GetStatus`, `GetServiceCapabilities`, and `AbsoluteMove` request objects are gone in favor of plain dicts at the call site, and `PtzAutoTrackerThread` is merged into `PtzAutoTracker`. Repeated blocks in the autotracker (waiting for the motor to stop, disabling autotracking on a failed setup step) are now single helpers.

* use camera config for autotracking enabled state

Camera processes read autotracking state from a shared `autotracker_enabled` value that the dispatcher and autotracker had to keep in sync with the config by hand. Camera processes now subscribe to the `autotracking` and `onvif` config updates and read `onvif.autotracking.enabled` directly, so the shared value and the autotracker's mirroring method are gone. `_disable` now publishes its change so the camera process hears about it. Also removes `tracking_active`, which was set and cleared but never read.

* compute max target box from live zoom factor

* fix autotracking debug overlay max target box lookup

* make max target box a function of zoom factor

frigate/app.py

@@ -77,7 +77,7 @@ from frigate.notices.registry import NoticeRegistry
 from frigate.object_detection.base import ObjectDetectProcess
 from frigate.object_detection.util import detection_frame_size
 from frigate.output.output import OutputProcess
-from frigate.ptz.autotrack import PtzAutoTrackerThread
+from frigate.ptz.autotrack import PtzAutoTracker
 from frigate.ptz.onvif import OnvifController
 from frigate.record.cleanup import RecordingCleanup
 from frigate.record.export import migrate_exports
@@ -166,11 +166,7 @@ class FrigateApp:
         # create camera_metrics
         for camera_name in self.config.cameras.keys():
             self.camera_metrics[camera_name] = CameraMetrics(self.metrics_manager)
-            self.ptz_metrics[camera_name] = PTZMetrics(
-                autotracker_enabled=self.config.cameras[
-                    camera_name
-                ].onvif.autotracking.enabled
-            )
+            self.ptz_metrics[camera_name] = PTZMetrics()
 
     def init_queues(self) -> None:
         # Queue for cameras to push tracked objects to
@@ -443,7 +439,7 @@ class FrigateApp:
                 )
 
     def start_ptz_autotracker(self) -> None:
-        self.ptz_autotracker_thread = PtzAutoTrackerThread(
+        self.ptz_autotracker_thread = PtzAutoTracker(
             self.config,
             self.onvif_controller,
             self.ptz_metrics,