There is definitely a need gap for providing censorship information on the movies. I think, the movie makers themselves are in the best position to offer a solution for this as they would have the censorship data from the film certification. They could just add this information to the imdb.
If this needs to be solved by others, then it would likely involve crowdsourcing effort and even then I wonder whether it would be possible for someone who watched a censored version of a movie to know what was censored unless they watch the uncensored version of the same (or) discuss at length about the movie with those who have watched the uncensored version.
I wonder whether it would be in the best interest of the movie makers, when the movie goers decide to not watch a movie in a particular country because it has been heavily censored and so wait for it to arrive on the Netflix. But, it would be definitely be in the best interest of the movie creator who wouldn't want their movie to be censored and the viewers.