Heads/Skulls facing the wrong way in inventory.

this is the vid to see textures are rong. look at the bunner in hand, too. i see the texture background.

I fixed the textures without skulls on banner.

Bug fixes skulls:

• include first person in skull.json

• include first person in skull_dragon.json

• include ["parent": "builtin/entity"] in skull_dragon.json
  (is better for dragon, because it´s an bigger skull)

• corrected "rotation"

• corrected "second person"

• corrected "display-gui"

• display "fixed" and "ground" were adapted to avoid further bugs.