Adds some metal variants to vanilla items

Items with variants:

• Big Bolt - Gold, silver, bronze
• Cash Register - Gold, silver, bronze
• Cookie Mold Pan - Gold, silver, bronze
• Egg Beater - Gold, silver, bronze
• Gold Bar - Silver, bronze
• Golden Cup - Gold, silver, bronze
• Garbage Lid - Gold
• Jar of Pickles - Gold
• Large Axle - Gold, silver, bronze
• Metal Sheet - Gold, silver, bronze
• Pro-Flashlight - Gold
• V-Type Engine - Gold, silver, bronze
• Gift Box - Gold, silver, bronze

All items are conductive. Some silver items look very close to their default counterparts, might be dealt with later. Also more items added later maybe

Formulas I made up for balancing the default weights

As of 0.0.6, these formulas are not exact but still used as a general guideline

Bronze

• Weight = Original weight+15%
• Value = Original value+40%
• Rarity = Averaged original rarity weight across all moons/3

Silver

• Weight = Original weight+30%
• Value = Original value+80%
• Rarity = Averaged original rarity weight across all moons/5

Gold

• Weight = Original weight+45%
• Value = Original value+120%
• Rarity = Averaged original rarity weight across all moons/7

Credits

• XuXiaolan and all contributers for making DawnLib
• Incase it isn't obvious, the ingots from Generic Scraps and LCGoldScrapMod inspired this mod
• Matty for Matty Fixes, which was used to calculate nicer item rotations