[MC-123824] Item particle commands do not use blocks' item textures to create particles, instead, they use the block particles

Run
```
/particle minecraft:item minecraft:enchanting_table ~ ~ ~ 1 1 1 0 100 force
```
→ Observe that instead of using break particles of the enchanting table's side, it instead uses the particle that is formed when breaking the enchanting table. (Obsidian.)

This can also be seen with

/particle minecraft:item minecraft:player_head ~ ~ ~ 1 1 1 0 100 force

Linked issues

It's probably like that because it's specified like that in the model files of the default assets.

Try the same commands in 1.12. It makes particles of all the block's sides, and skulls would make their own particles, not soul sand.

Can confirm that this issue is still present in 21w05b.

Can confirm in 21w06a.