UUID references to other entities are not stored as UUIDMost and UUIDLeast for tamable entities

The bug

Some entities which store UUID references to other entities do not store them as combination of UUIDMost and UUIDLeast but instead as string.

Storing it split is done by all newer entities like area_effect_cloud, evocation_fangs and llama_spit.

Affected entities

• horses, mules, donkeys...: OwnerUUID
• tamable entities (wolves, ocelots, ...): OwnerUUID