sortM features

[aminya]

Different tasks of this to do plan:

1. implement NaN, undef, missing placement options.
2. Implement comparison method for complex numbers.
3. Implement multidimensional (3D and more) for sortperm missing sortperm(A, dim)? JuliaLang/julia#16273

Achievement check:

The condition that should be met or the test that should be done to close the issue. This can be doing all the tasks.