Frostbite throwing captions are inconsistent with other mobs that throw things

Relates to MC-177110 and MC-312319.

The new frostbite entity can throw ice balls at things. When throwing them, the subtitle produced with closed captions enabled appears to match that which is shown when a player throws said item. This matches the existing behaviour of snow golems throwing snowballs, but does not match the behaviour of witches throwing potions, therefore creating an inconsistency.

To fix, either a generic item-based caption should be used for all of them, or entity-specific throwing captions should exist for all of them.