Works with nested shulkerboxes

[aria1th]

1. Fake / shadow player will refill hotbar as default
2. command makes toggleable for real players
3. Refilling now works with fake player block placing
4. Refilling works with nested shulker boxes (but it won't try to refill shulker box)

[rv3r]

Two questions:

1. Not that it should matter, do you use one particular mod (and perhaps game version) for shulker nesting? I want to check the script under the same conditions, but the rules database presents 3 mods with this feature.
2. Is there any particular reason you modified this script and not any other inventory management script? Just curious (but definitely thinking about adding this to my library...)