Add ability to configure genai to use snapshot instead of thumbnails (#14077)

* Allow embedding of snapshot for description via config option

* docs

* frontend button

* Backend

* crop snapshot to region

* only show dropdown when event has snapshot

* fix cursor on dropdown

* crop on initial generation as well

* use enum for type

* fix type

frigate/events/types.py

@@ -12,3 +12,8 @@ class EventStateEnum(str, Enum):
     start = "start"
     update = "update"
     end = "end"
+
+
+class RegenerateDescriptionEnum(str, Enum):
+    thumbnails = "thumbnails"
+    snapshot = "snapshot"