Store name of the user who added a song

[Jokler]

Is your feature request related to a problem? Please describe.
If a user joins the channel after the playlist has been filled they can't see who requested a song.

Describe the solution you'd like
On add the bot should check what the name of the message sender was and store it to display it later. This could be used in multiple places like in the message that gets sent when a new song starts.