Shutdown hang (#11793)

* intentionally handle queues during shutdown and carefully manage shutdown order

* more carefully manage shutdown to avoid threadlocks

* use debug for signal logging

* ensure disabled cameras dont break shutdown

* typo

frigate/util/builtin.py

@@ -3,6 +3,8 @@
 import copy
 import datetime
 import logging
+import multiprocessing as mp
+import queue
 import re
 import shlex
 import urllib.parse
@@ -337,3 +339,13 @@ def clear_and_unlink(file: Path, missing_ok: bool = True) -> None:
         pass
 
     file.unlink(missing_ok=missing_ok)
+
+
+def empty_and_close_queue(q: mp.Queue):
+    while True:
+        try:
+            q.get(block=True, timeout=0.5)
+        except queue.Empty:
+            q.close()
+            q.join_thread()
+            return