Per-Player Keep Inventory

The mod adds the ability to set each player to have keep inventory individually via commands.

It also allows for giving each player a number of keep inventory lives"lives" that they lose 1 of each time they die.

There is also a new set of game rules that allows an admin to set each life to also grant 1 additional heart, along with a maximum number of additional hearts that can be granted.
This feature is heavily inspired by a the same feature in the Matcha Flavored datapack.

Set a players keep inventory rule to true or false:
/keepinventory {player} {true || false}

Manipulate the number of free keep inventory lives a player has:
/keepinventory {player} add_life <amount>
/keepinventory {player} set_lives <amount>
/keepinventory {player} get_lives

Gamerules:
/gamerule playerkeepinventory:extra_life_health_bonus {true || false}
/gamerule playerkeepinventory:max_extra_hearts <amount>