Broken out from #18627 to track separately. This has several parts, in increasing order of complexity:

• Sorting for specialized lists (int/float/Tensor). This should be a simple call to std::sort, since the appropriate comparison ops are already defined.
• Sorting for generic lists. This will require implementing comparison for generic IValues.
• Sorting for ScriptClasses. This is different from generic lists because the operator will need to call the appropriate comparison method (__gt__ or whatever) on the script class.