Need to use BoW to speed up frame registration

[vadixidav]

Currently, frames are registered directly against all features using the hnsw crate. This is effective, but it is not sufficiently fast for realtime application. One technique that would be important to add is bag of words (BoW). Typically, in this approach the frame is segmented into chunks and the features within those chunks are dimensionally reduced and treated as visual words for the purposes of BoW.