[BUG] Inconsistency between cornac bpr function signature and docstring

Description

https://github.com/recommenders-team/recommenders/blob/c98accb5b476bf3f4119f229d77ad8765f3295ca/recommenders/models/cornac/bpr.py#L20-L38

The function signature has col_prediction but the docstring refers to col_rating

Willingness to contribute

• Yes, I can contribute for this issue independently.
• Yes, I can contribute for this issue with guidance from Recommenders community.
• No, I cannot contribute at this time.