Kettle overhaul

• Container slot in ui now shows a cup sprite when empty
• Appearance swap system reworked, now works for both block and item form
• New netherite variant which brews twice as fast and is fireproof like other netherite items
• Greatly expanded kettle's capabilities:
  • Kettle can now drain fluids directly from world or other fluid tanks
  • Kettle can now fill other fluid tanks with it's contents and be used to fill offhand containers with appropriate fluid. -Tooltips have been added that show which of these functions are currently available (based on kettle's contents)
• Updated kettle item model to support head item render (reference)
• Kettles now render a tray below them when placed above campfire