Feature description

Rework the Frost trim to move some of its visual feature to two new trims: Glacial and Snowman, and then make the Frost trim more frosty. This will affect existing trims, but it's a 2.0 update so that's allowed, right?

Checklist:

• Add a new rare Glacial Trim, that only drops from Ominous Icy Trial Spawners in the Frostologer Castle
• Make the Frost Trim drop from regular Icy Trial Spawners in the Frostologer Castle
• Add a new Snowman Trim, that can be found in Chillager Outposts
• Make the Frost trim actually look frosty, with bits of Frost enveloping the player
• Make the Frost Trim helmet have horns on the side like the Skyrim iron helmet
• Move the crown feature to the Glacial Trim helmet, and make the theme of the glacial trim fit something like a Viking theme/border
• Move the snowman buttons to the Snowman armor trim, and give that trim's helmet a carrot for a nose :D
• Add an advancement for gathering all trims from Frostiful