[FEA] CAGRA to support cosine and inner product distance

[cjnolet]

trafficstars

Today we could do this by normalizing the vectors and using euclidean distance (to get the angular distance), but that requires preprocessing on the user's side. We should support cosine distance as a first-class option.

[jianshu93]

Hello Team,

I am also wondering whether distance like hamming distance (normalized) can be provided between 2 vectors, in addition to L2 norm.

Thanks,

Jianshu