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.

SongRow.tscn

@@ -17,6 +17,7 @@ layout_mode = 2
 size_flags_vertical = 0
 
 [node name="SongListLabel" type="Label" parent="HBoxContainer"]
+unique_name_in_owner = true
 texture_filter = 2
 custom_minimum_size = Vector2(865, 28)
 layout_mode = 2
@@ -34,6 +35,7 @@ size_flags_horizontal = 3
 size_flags_vertical = 0
 
 [node name="SongListPlayers" type="HBoxContainer" parent="HBoxContainer"]
+unique_name_in_owner = true
 layout_mode = 2
 size_flags_vertical = 0