ML-Herbarium: Feature overhaul matching

Overhauls the matching function with the following improvements:

Employs to structural pattern matching
Uses RapidFuzz instead of difflib
Is now multithreaded
Uses the sum of OCR confidence and matching similarity as a score to choose the best match
Improves matching speed 10x
Lowers minimum OCR confidence threshold to 15% so more matches are considered

BU-Spark / ml-herbarium