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/api/defs/regenerate_query_parameters.py

@@ -0,0 +1,9 @@
+from typing import Optional
+
+from pydantic import BaseModel
+
+from frigate.events.types import RegenerateDescriptionEnum
+
+
+class RegenerateQueryParameters(BaseModel):
+    source: Optional[RegenerateDescriptionEnum] = RegenerateDescriptionEnum.thumbnails