feat: Support move limits in setActivePlayers

[delucis]

Continuing work towards #445

• Support moveLimit option in setActivePlayers, storing result in ctx._activePlayersMoveLimit

• Track moves by currently active players in ctx._activePlayersNumMoves

• Reset player counts whenever setActivePlayers is called and when the turn ends

• End stages when player has reached move limit

• Remove once option in favour of moveLimit

• Restore previous move limits and counts when using revert: true

[delucis]

@nicolodavis Let me know if you think anything needs changing here.

I think it's ready to merge, but you might have better ideas for variable naming or more efficient implementations.

[nicolodavis]

Will take a look soon. A bit busy this weekend, so probably sometime on Monday. Thanks for the great work!