LPR improvements (#20129)

* continue to use paddleocr v3 text detection model for large

v5 was not finding text on multi-line plates at all in testing

* implement clustering of plate variants per event

should reduce OCR inconsistencies and improve plate recognition stability by using string similarity to cluster similar variants (10 per event id) and choosing the highest confidence representative as the final plate

* pass camera

* prune number of variants based on detect fps

* implement replacement rules for cleaning up and normalizing plates

* docs

* docs

docs/docs/configuration/reference.md

@@ -661,6 +661,8 @@ lpr:
   enhancement: 0
   # Optional: Save plate images to /media/frigate/clips/lpr for debugging purposes (default: shown below)
   debug_save_plates: False
+  # Optional: List of regex replacement rules to normalize detected plates (default: shown below)
+  replace_rules: {}
 
 # Optional: Configuration for AI generated tracked object descriptions
 # WARNING: Depending on the provider, this will send thumbnails over the internet