item enhancement workbench

feature: a mid game workbench.
features:
- additional rare drops (material used for enchanting)
- workbench that can be crafted early into "hardmode" (not sure what's the official lingo, using terraria lingo) used for enchanting tools with the added drops

more specific ideas for the features:
- drop would be a "[mineral name] powder" one for each biome
- powders drop only after getting into hardmode, can be crafted into gems (due to overlap with the existing gems, I believe it should be fine to give the existing gems additional purpose for this feature, or rebalancing the item level system)
- each gem upon dropping/creation will get a random stat bonus based on a table specific for this biome's gem. having dmg up type stats as common and %chance to burn/turn % of fishing into range damage type stats as rare/epic.

specific enchant ideas:
- ads a boat tracker on map
- gives a jump ability to boat
- piercing for projectiles
- damage type change phys/magic