Adjust the XP Formula for Combining/Attaching Enchantments

This was the most reasonable, easiest change that I could think of to alleviate some issues with the villager trade rebalance, which would let players find more value in the positive aspects of the changes.

The problem right now is that the XP cost for enchanting can become very expensive, very quickly. If a player doesn't plan out their enchantments well, they can stumble into a scenario where they would have to fork out upwards of 200 levels to make their ultimate piece of gear, which isn't a realistic endeavor for most players.

Before, there used to be a cap on combining/attaching gear, such that it became 'too expensive,' and the game wouldn't let you proceed. My suggestion is to bring back the cap, but remove the prohibitive part of it. So if the cap was 42 levels worth of XP, players would still be able to combine/attach enchantments, but it would never become more expensive than 42 levels. Additionally, the rate at which combining/attaching enchantments becomes more expensive could be reduced, but this would be less important if there was a cap.

This change would be great for a variety of reasons:

• Players can still punish themselves for bad enchantment planning, but not to a point of no realistic return, where they would have to start over. There would be no pressure to save enchantments for later
• Low level enchantment books would feel much more useable
• Having perfect librarian trades would be less important
• RNG for enchanted books/equipment loot would feel less brutal