"Add shortcut to desktop" button for servers

[VasilisThePikachu]

Requires #136

With the above, you can make shortcuts yourself via right click → shortcut and enter a ss14/ss14s address. But it would be awesome if the launcher could automaticly make these.

Prop3 and uuid is always the same, IDList seems to always be empty. Looking into steam game shortcuts you can also provide an IconFile to an icon. Maybe it would be cool if we pull the RPC icon for the server somehow so that the shortcut would have the specific servers logo.