PERF: sort_values speedup for multiple columns with random numeric values
Continue work on #17141.
Speedup achieved for sorting by multiple columns: lexsort over multiple columns
replaced with mergesort of columns in reverse order than specified in "by"
argument of DataFrame.sort_values().
Issues:
- only works for numerical data
- only random enough data achieve sorting speedup (no factorization)
- ASV of one-column sort is worse, why?

- [ ] closes #xxxx
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry
