Move upgradeable check to :upgrade action knocking ~10s off each LWRP call

After some analysis on our systems we found that each chocolatey LWRP call with the default action of :install was taking close to 20s.  By moving the upgradeable check the upgrade action we reduced this to 3-4s.  For users with even a handful of chocolatey packages this change considerably reduces the chocolatey runtime.
You can directly use `if upgradeable?(@current_resource.package)` ;)