Blocks don't retain custom names when dropped with /setblock destroy

Doesn't only affect shulker boxes. Affects all blocks that drop with nbt. Perhaps the title and description should be changed a bit.

Affects:

• renamed container → name doesn't get stored ❌

• player heads → texture gets stored correctly ✔

• banners → pattern gets stored correctly ✔

• shulker boxes → item doesn't drop ❌

• signs → text doesn't get stored (intended) ✔

• flower pots → both flower and flower pot drop ✔

All cases fail and give an error message though.

In 18w31a Shulker Boxes aren't affected anymore, other renamed Containers still are.