tsk-62: Use QueuedSong and QueuedCoverArt to replace references to path of Song and CoverArt (#64)

Closes #62

Reviewed-on: #64
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

Cargo.lock

@@ -1322,7 +1322,7 @@ dependencies = [
 
 [[package]]
 name = "songparser"
-version = "0.4.6"
+version = "0.4.7"
 dependencies = [
  "futures",
  "icarus_envy",