Query player XP and Level from script

Currently we can affect the player's XP level using commands, but there doesn't seem to be a way to query what a player's XP total is or their current 'level'. It would be great to have a new component we could use to check the player's current xp and level totals, so we could gate features based on how much xp the player has in our add ons.

For example it would be great to be able to make a spell system where the player can gain access to more powerful abilities whilst at higher xp levels. It would also allow us to create abilities that 'cost' xp to use, but aren't available if you don't have the required amount of xp available to pay for it.