Stores the Pot object to be used as the main pot. This is the initial pot used to store bets that players make. If a player goes ALL_IN, then this pot is no longer used and a side pot is created and added to sidePots. In the BettingRound.SHOWDOWN, this pot is split amongst all players.
sidePots
MutableList<Pot>
Starts empty but when a player is forced to go PlayerStatus.ALL_IN, because they are unable to contribute to the Pot any longer, a side Pot is created in this list. A side Pot, once created, will be contributed to instead of the mainPot. In the BettingRound.SHOWDOWN, each side Pot is split amongst all players that contributed to it.