Dynamically enable/disable cameras (#16894)

* config options

* metrics

* stop and restart ffmpeg processes

* dispatcher

* frontend websocket

* buttons for testing

* don't recreate log pipe

* add/remove cam from birdseye when enabling/disabling

* end all objects and send empty camera activity

* enable/disable switch in ui

* disable buttons when camera is disabled

* use enabled_in_config for some frontend checks

* tweaks

* handle settings pane with disabled cameras

* frontend tweaks

* change to debug log

* mqtt docs

* tweak

* ensure all ffmpeg processes are initially started

* clean up

* use zmq

* remove camera metrics

* remove camera metrics

* tweaks

* frontend tweaks

frigate/config/camera/camera.py

@@ -102,6 +102,9 @@ class CameraConfig(FrigateBaseModel):
     zones: dict[str, ZoneConfig] = Field(
         default_factory=dict, title="Zone configuration."
     )
+    enabled_in_config: Optional[bool] = Field(
+        default=None, title="Keep track of original state of camera."
+    )
 
     _ffmpeg_cmds: list[dict[str, list[str]]] = PrivateAttr()