Reach nodes by unique name instead of long paths

Nodes a script uses through a path of several nodes are marked unique in their
scene and found with %Name. The search list is renamed SearchResults, and the
player row's nodes get their real types.

MusicListPanel.tscn

@@ -17,6 +17,7 @@ follow_focus = true
 script = ExtResource("7_dj026")
 
 [node name="MusicList" type="VBoxContainer" parent="ScrollContainer" unique_id=373398568]
+unique_name_in_owner = true
 layout_mode = 2
 size_flags_horizontal = 3
 size_flags_vertical = 3