Lexical similarity

[idarav]

This one is a bit complex, check legacy implementation.
https://github.com/FrontEndART/project-kb/blob/master/prospector/rank.py#L673

[copernico]

I would put this on hold, we can rediscuss when the rest is working...

[copernico]

FYI: SAP is working on this already (i will create a corresponding issue upstream to keep track of this)