DFTI performance improvement

[TobiasErnst]

In the current implementation of MKL.NET a descriptor is created for every DFT. If you need to run similar DFTs with only different data this results in a not needed overhead due to memory allocations.

Therefore the methods DftiCreateDescriptor and DftiFreeDescriptor should also be accessible via MKL.NET and it should be possible to inject an already created descriptor to all other Dfti methods.

I am willing to implement this but I currently have a problem with the Package-Native.ps1 whish throws the error

Exception calling "DownloadFile" with "2" argument(s): "The remote server returned an error: (403) Forbidden."
At D:\MKL.NET\Scripts\Package-Native.ps1:22 char:9
+         $wc.DownloadFile($source, $localFilename)
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : WebException

for DownloadFile https://registrationcenter-download.intel.com/akdlm/irc_nas/18444/l_onemkl_p_2022.0.1.117_offline.sh "$PSScriptRoot/../packages/l_onemkl_p_2022.0.1.117_offline.sh"