Fish refactor. (#65785)

Refactors fish into proper paths.
Removes aquarium behaviour intermediary datums.
Moves fish functionality out of aquarium content component.
Fixes flopping animation resetting on dropping.

Simplifies everything. There should be no player facing changes.

The animate signal is kinda weak method of solving the animate queue issue but it seemed least intrusive to me.
Open to any better ideas.

code/game/objects/structures/maintenance.dm

@@ -25,7 +25,7 @@ at the cost of risking a vicious bite.**/
 		/obj/item/restraints/handcuffs/cable/pink = 1,
 		/obj/item/restraints/handcuffs/alien = 2,
 		/obj/item/coin/bananium = 9,
-		/datum/aquarium_behaviour/fish/ratfish = 10,
+		/obj/item/fish/ratfish = 10,
 		/obj/item/knife/butcher = 5,
 		/obj/item/coin/mythril = 1,
 	)
@@ -33,16 +33,14 @@ at the cost of risking a vicious bite.**/
 
 /obj/structure/moisture_trap/Initialize(mapload)
 	. = ..()
+	ADD_TRAIT(src, TRAIT_FISH_SAFE_STORAGE, TRAIT_GENERIC)
+	AddElement(/datum/element/swabable, CELL_LINE_TABLE_MOIST, CELL_VIRUS_TABLE_GENERIC, rand(2,4), 20)
 	if(prob(40))
 		critter_infested = FALSE
 	if(prob(75))
 		var/picked_item = pick_weight(loot_table)
-		if(ispath(picked_item, /datum/aquarium_behaviour/fish))
-			hidden_item = generate_fish(src, picked_item)
-		else
-			hidden_item = new picked_item(src)
-	AddElement(/datum/element/swabable, CELL_LINE_TABLE_MOIST, CELL_VIRUS_TABLE_GENERIC, rand(2,4), 20)
-	ADD_TRAIT(src, TRAIT_FISH_SAFE_STORAGE, TRAIT_GENERIC)
+		hidden_item = new picked_item(src)
+
 
 /obj/structure/moisture_trap/Destroy()
 	if(hidden_item)