Make allays more reliable and less obtrusive

Allays already can't be accidentally punched by the player, but they still block the player from placing or breaking blocks behind them. Interactions should pass through tamed allays completely, meaning I can mine or place blocks behind an allay as if it isn't even there.

Allays are also able to push the player around, which shouldn't be possible if they are tamed by that player. They should just pass through players without any collisions.

Allays tend to wander when their owner leaves a multiplayer world, and can travel hundreds of blocks over time. When a tamed allay's owner leaves, they should stay in that general area and return to the player when they rejoin.

Alternatively, maybe allays should leave the world with the player and spawn back in when the player rejoins. Their nbt data would have to be stored with the player data when a player leaves for this to work