Shulker's solid collision box hard-coded

Partner Rank: 4

Verification builds: 1.13.0.4
Regression builds: Never worked as far as I know

Summary: Shulker entities (including ones using a runtime_identifier of "minecraft:shulker") do not use minecraft:collision_box to set their solid collision box.

Impact: Entities with solid collision boxes are generally a very useful tool to work with. Does not affect content

Repro Steps:

1. Apply the attached behavior pack to a world
2. Spawn a shulker and observe the result

Observed Results: Solid collision box has still size of a block

Expected Results: Solid collision box has size of a slab

Notes: If the shulker entity is riding another entity, minecraft:collision_box seems to work inconsistently.