Feature description

Update the loot in the Frostologer Castle boss room to better suit vaults

Checklist:

• Add a Frost Rod
• Make the Frost Wand craftable from rods + icicles + Glacial Heart
• Remove Frostologer drops
• Make the Icy Vault in the Frostologer's Throne room guarantee a Glacial Heart
• Remove the Inert Frostology Cloak crafting recipe
• Make the Inert Frostologer Cloak only drop from an Ominous Frostologer vault