Mobs can't play sounds underwater

Verification builds: 903984 1.4.0.3_RC3

Summary: Land mobs are hard-coded to not play sounds when they're underwater. However, with the Aquatic Update, it would be good to have control over this sound muting.

Impact: Inability for content creators to make new and interesting mobs for underwater use without being limited to only current underwater mobs

Repro Steps: Place any land-based mob (like a pig) in water and try hurting it.

Observed Results: No 'hurt' sound will play

Expected Results: You should hear a 'hurt' sound for feedback