Mpris player name

[MHoogesteger]

Add an option in the config file to specify the Mpris player name. This prevents sptlrx from trying to load lyrics to a video which is (later) opened in a browser for example when the "real" player is running in the background and not first in the list.

Name should be specified as follows:

mpris: 
    name: "org.mpris.MediaPlayer2.spotifyd" 

where spotifyd should be replaced with the player name as given by playerctl -l.

[MHoogesteger]

Haven't created an issue for this behavior, but this change allows one to fix the mpris player to spotifyd or any player, and prevent switching on opening video tabs in the browser (and thereby errors such as "...MediaPlayer2.Player Position is not supported", depending on the player).

[raitonoberu]

Thank you, this is a very useful feature.