Bingo-esque Lab improvements

A few ideas for improving lab.

* Add improved Offering to Tribute final chest pool (Tribute can't drop offerings at all, currently)
* Higher chance (i.e. 50% instead of current ~10%) to drop improved offerings from final lab chests (or make it guaranteed)
* Fix the lever hitbox so you can flip them from their narrow ends. So annoying.
* Kirac offer Improved Labyrinth Trial missions
* Allow Control-C to copy gem information on divine font
* Add gold jackpots to lab chests (lab is very gold-scarce, currently).
* Lower gold cost for trading high level/quality gems in the merchant shop

You had me at Bingo.