Refactor event cleanup to consider review severity (#15415)

* Keep track of objects max review severity

* Refactor cleanup to split snapshots and clips

* Cleanup events based on review severity

* Cleanup review imports

* Don't catch detections

frigate/review/maintainer.py

@@ -7,7 +7,6 @@ import random
 import string
 import sys
 import threading
-from enum import Enum
 from multiprocessing.synchronize import Event as MpEvent
 from pathlib import Path
 from typing import Optional
@@ -27,6 +26,7 @@ from frigate.const import (
 from frigate.events.external import ManualEventState
 from frigate.models import ReviewSegment
 from frigate.object_processing import TrackedObject
+from frigate.review.types import SeverityEnum
 from frigate.util.image import SharedMemoryFrameManager, calculate_16_9_crop
 
 logger = logging.getLogger(__name__)
@@ -39,11 +39,6 @@ THRESHOLD_ALERT_ACTIVITY = 120
 THRESHOLD_DETECTION_ACTIVITY = 30
 
 
-class SeverityEnum(str, Enum):
-    alert = "alert"
-    detection = "detection"
-
-
 class PendingReviewSegment:
     def __init__(
         self,