Implement turn counter overflow with Wish / Future moves

[DaWoblefet]

Big credit to Anubis for assisting in research and Karthik for help in implementation.

One implementation quirk Showdown has is that we treat Team Preview and everything before the first move selection as "turn 0", instead of everything up to the second move selection as "turn 0" (i.e. the first turn). If that was implemented correctly, we probably wouldn't need the hardcodes we have for things like Burning Jealousy vs Download. However, there's a lot of stuff that looks like it depends on the current turn count implementation, so I didn't touch that and just tossed in some -1s where appropriate.

See discussion of this mechanic starting at this post: https://www.smogon.com/forums/threads/10350377