Yes, Codechef has such feature. Just move your mouse over the area containing the number of submissions, (on the 3rd column from the left side). You will get to how many many users got how many points, partial or full. This feature is available for contests. In the practice section, you can just see the number of users who solved the question fully. I don’t think it makes any reason to show how many users solved the question partially in the practice section as the solutions are visible and editorials out there to help you get full points. Thus, we may judge the difficulty in practice section just by looking at the number of submissions with full points.
Also the accuracy of the problem is calculated as the number of solutions will full points divided by the number of submissions made. This will fairly give you an idea about the difficulty of the problem in terms of corner cases as well.
Also, when you open the practice section or any contest page, all the problems are already sorted on the basis of difficulty, i.e. ones with more correct submissions first and if 2 solutions have same number of submissions, they are sorted on the basis of their accuracy.
If you feel your question was answered, mark it as accepted.