psl-native library appeared at the time of the first version .Net Core 1.0 which had many limitations.
Currently we moved to .Net Core 2.1 and we need to review psl-native library code and remove unneeded p/invokes. Ideally we could remove this library altogether.

TODO Tasks (Please check when it's finished):

• Remove the native .cpp code related to the changes in Cleanup FileSystem provider #6909 from psl-native
• Remove the native .cpp code related to the changes in Cleanup NonWindowsGetDomainName() #6948 from psl-native
• Remove the native .cpp code related to the changes in Cleanup NativeItemExists() #6929 from psl-native