Allow users to set a distance threshold to consider two vectors a "very similiar"

[eddyxu]

Problem Statement

For example, I have lots of images that are resized jpgs and gifs -- the hashes are technically different, but the vector l2 distance is tiny then there's deduplicating things like images and watermarked images -- i also want this to be grouped together and to pick just one which basically uses the vector distance again, but with a looser threshold

[changhiskhan]

Help wanted: if anyone can do a simple POC that determines what the optimal technique is, we can implement the rest in Rust