Title Screen QOL Theming

This was supposed to be a quick quality of life addition for the Title Screen that applied the save and theme to the menu, but then I discovered a new bug I had to bypass with the character palette when doing it. So I ended up doing a bit more related to the Title Screen as a result.

I also *had* a function which checks for the number of valid folders within the Pck to see how many worlds there are, but I think it might've been a bit slow so I replaced it with constant values.

- Save for the currently loaded campaign gets applied on startup
- Backing out of World 9 and over keeps you on said worlds at the title screen
- Added Skyland and Volcano to SMB1 themes since it shares most of its themes with Lost Levels
- Fixed Title Screen Stars for the Volcano Theme

Scripts/UI/TitleScreenOptions.gd

@@ -21,7 +21,7 @@ func _process(_delta: float) -> void:
 		handle_inputs()
 
 func open() -> void:
-	Global.world_num = clamp(Global.world_num, 1, 8) # have this, cause i cba to make a fix for backing out of world 9 keeping you at world 9
+	Global.world_num = clamp(Global.world_num, 1, Level.get_world_count())
 	title_screen_parent.active_options = self
 	show()
 	await get_tree().physics_frame