Handle identical embeddings

[joshhochuli]

Current approach is to inject a tiny amount of noise, not sure this is ideal. If we ever do exact checking of embeddings this will cause errors.

[jimmyjbling]

do we know the side effects of identical embedding? Is it that the KD tree cannot handle them or is it just an issue we noticed about the data

A little but a of elbow grease and Longleaf would allow me to make a steriochemically flat Enamine database set that would in theory remove any chance of identical embedding. Might be easier than trying to fix the code