The Undergarden

- added the Forgotten, an armored skeleton that roams the halls of the catacombs.
- added the S'Mog, a taller, smoggier version of the mog found in the Smog Spires and Barren Abyss
- added Blue Mogmoss, obtained from shearing a S'Mog
- added Blue Mogmoss Rug
- added Slop Bowls, a disgusting bowl of moss and beans that can be found in the Catacombs
- added a bunch of Vestige structures scattered around the dimension
- added the Frosty Smogstem Forest, a colder variant of the Smogstem Forest
- added a portal travel animation, similar to the nether portal one
- added a config option to turn off the fog in the dimension
- added Powdered Snow patches to the various different cold biomes
- spawners in the Catacombs will now only spawn forgotten instead of various other creatures in the dimension
- stoneborn will no longer trade Cloggrum Battleaxes. They will now need to be obtained from Forgotten in the Catacombs who will sometimes be carrying one
- removed the ability for Stoneborn to regenerate health over time
- mobs that are immune to Blisterberry Bushes are now controlled through a new tag `undergarden:immune_to_blisterberry_bush`
- fixed fog flickering underwater
- fixed chest boats from the mod not having recipes
- fixed the Barren Abyss not generating the correct blocks on the surface
- fixed Dead Sea using Bog sounds