Fix "Spotify not found" for the Windows Store version of Spotify

[cjhesse]

This fixes the "Spotify not found" issue (#261) by checking for a media session name that matches what the Windows Store version of Spotify uses. I was not able to get the feature that starts Spotify on launch working, but the mute feature does. I did not the blocking of banner ads.

There's another pull request (#262) that attempts to fix this issue, but it only adds a default path to find where Spotify.exe is. I didn't find that this fixed the issue.