Piglin brutes should drop much more EXP

It's nice to see a stronger variant of Piglins being added to the game, but I find it weird that they drop practically nothing of use. Obviously, they can't drop gold because normal Piglins will just barter with it or steal it from the dead Piglin Brutes, so the best way to reward the player for overcoming these brutes should be a lot more EXP than usual.

As of 20w27a, they drop 5 EXP, the same as normal monsters in the Overworld. I propose bumping it up to 20 EXP, mostly because other mobs that are tougher and drop similar amounts of EXP also give rare items, while Piglin Brutes give none. If that's too much, though, it should at least be 10 EXP.