Feature Request: Fish AI, and Drowned ability to walk underwater

1) Please add fish AI (salmon, cod, or tropical fish) under AI and Goals > Entity Base
The only current aquatic in there is squid and boi does that not do what we need. Please add a fish AI base so aquatics can be more easily made: movement, schooling, drowning on land, etc.

2) Please add a procedure or AI task to be able to walk underwater on the sea floor (essentially enabling bottom-dwelling mobs/creatures/entities). Drowned can do it, no matter how far from land or deep in the water they are. I've seen many people ask how to do this. "aquatic" ai only swim around, "land" ai stop walking when they get too far from land/deep in water.