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

web/src/views/settings/NotificationsSettingsView.tsx

@@ -80,7 +80,7 @@ export default function NotificationView({
     return Object.values(config.cameras)
       .filter(
         (conf) =>
-          conf.enabled &&
+          conf.enabled_in_config &&
           conf.notifications &&
           conf.notifications.enabled_in_config,
       )