SIFT scores from VLFeat

[mihaidusmanu]

There is no easy way to get detection scores out of VLFeat. The current approach is very hacky and bug-prone as I recover the scores directly from the DoG pyramid. The following line should be thoroughly verified.

https://github.com/mihaidusmanu/pycolmap/blob/61fbe2748a15717fcbeaee717fb5a1405f978c34/sift.cc#L102

[ahojnnes]

How about making this change inside COLMAP? We can extend the FeatureKeypoint struct with a score and also extend the SQLite database schema with an extra column.