This PR adds animated tilesets! I spent the day working on these, and it wasn't easy. This is primarily to help animate the All-Stars' grass tiles. You should be able to animate the other tilesets as well, but I haven't tested them.
JSONs are provided in the assets for Conveyer Belts and Liquids. There's two ways to animate the tilesets. The first is by the traditional way as used by `AnimatedSprite2D`, and the other is by how Godot animates tilesets normally as seen with the conveyer belts and liquids.
The last thing is that while doing this, I actually managed to fix the Resource Pack bug where reloading also reloads the blocks! It was surprisingly straightforward. I just edited the `BlockClass.gd` file to erase the cells when a block is hit or destroyed.
Let me know if you have any suggestions for things I should change or fix.
This PR changes the End Final Castle to use the Special visuals when the level is in the SMBS campaign.
This is primarily for the Level Editor / Custom Levels and isn't really necessary for the main campaigns. Hence the added check to see if the Level Editor is used.
