Introduce a drop player head effect

[baailey]

Is your feature request related to a problem? Please describe. Currently there is no way to have a player's head drop when they are killed by another player. Implementing this effect will allow us to create enchants that used to exist, which player's enjoyed.

Describe the solution you'd like I would like an effect to be added that allows specifying you want a player's head to drop when they are killed.

Describe alternatives you've considered I have played around with drop_item_for_player when using kill as a trigger, however that allows the player_head item to drop even when killing mobs. Additionally, there is no known way to have the player_head item drop with the player skin attached.

Additional context Add any other context or screenshots about the feature request here.