bug(windows): check cache downloaded files are still the latest in waiting restart state.

As noted when completing #13767.
In the `WaitingRestart` State and receiving a `check for updates` event the requirement is if newer updates are found then what is already in the cache return to the `UpdateAvailable` state so that the newer updates can be downloaded.
It was noted that it was actually just comparing against the installed versions rather then the files in the cache.
There is TODO in the code where this needs to be updated.