Trying to parallelize using CUSOLVERRF.jl with @threads

@mhunke
I interfaced exactly what you need a few days ago.
With the latest release of cuDSS we can now solve a batch of linear systems with the same sparsity pattern.

I interfaced the feature and added some examples in the documentation:

I worked on it for a project with MadNLP.jl but I’m glad if it can be useful to other people.