(PUP-2385) Puppet::Util::Windows::File refactor

 - Use wide_string as mixin from Puppet::Util::Windows::String
(PUP-2385) FFI Puppet::Util::Windows::File

 - Convert Windows MoveFileEx to FFI
 - No longer need to require 'windows/api'
Merge branch 'ticket/master/PUP-2385-FFI-Windows-File'

* ticket/master/PUP-2385-FFI-Windows-File:
  (PUP-2385) FFI Puppet::Util::Windows::File
  (PUP-2385) Puppet::Util::Windows::File refactor