Add ncspot support

[diniamo]

Hear me out, I've read the Reddit threads saying it's not possible. The reason given for that was: you cannot get the position of the player because ncspot doesn't interact with the API.

However it's possible to use the MPRIS D-Bus interface, which allows us to get the metadata (track id included) and position of the currently playing media in ncspot.

I thought I would make an issue before trying to implement it myself, as I don't like typescript, and practically recreating the whole project in a different language would take quite a bit of effort.