Fish no longer dies when flopping on safe water. (#90024)

## About The Pull Request
I've been feeling for some time that fishes dying if placed on fishable
water (or lava/plasma for a couple ones) to be kinda lakluster and
counterintuitive. YakumoChen opening an issue about it proved I wasn't
the only one thinking that, and I'm not feeling like starting with
adding fishing stuff just yet. Not without improving the existing
content first.

The source_types file was also getting big and a bit bad to navigate
through, so I've decided to split it into half a dozen distinct files:
fishing portals, rifts, turfs, structures, mining/ruins and surgery.

## Why It's Good For The Game
This fixes #89872.
The files should also be bit more organized now.

## Changelog
🆑
fix: Fish will no longer drown if left half-submerged in a fishable turf
on which it can normally be found. Instead it will disperse after a
while or if starving. Note that this only happens if the fish is native
to such turfs (eg. lavaloop on beach water will still die).
/🆑

code/controllers/subsystem/processing/fishing.dm

@@ -13,6 +13,8 @@ PROCESSING_SUBSYSTEM_DEF(fishing)
 	var/list/fish_properties
 	///A cache of fish that can be caught by each type of fishing lure
 	var/list/lure_catchables
+	///A list of fish types with list of turfs where they can happily hop around without dying as assoc value
+	var/list/fish_safe_turfs_by_type = list()
 
 /datum/controller/subsystem/processing/fishing/Initialize()
 	..()
@@ -102,4 +104,19 @@ PROCESSING_SUBSYSTEM_DEF(fishing)
 
 	QDEL_LIST(spawned_fish)
 
+	//Populate the list of safe turfs for several fishes
+	for(var/source_path in GLOB.preset_fish_sources)
+		var/datum/fish_source/source = GLOB.preset_fish_sources[source_path]
+		if(!length(source.associated_safe_turfs))
+			continue
+		for(var/fish_path in source.fish_table)
+			if(!istype(fish_path, /obj/item/fish))
+				continue
+			LAZYOR(fish_safe_turfs_by_type[fish_path], source.associated_safe_turfs)
+	//If a subtype doesn't have set safe turfs, it'll inherit them from the parent type.
+	for(var/fish_type as anything in fish_safe_turfs_by_type)
+		for(var/fish_subtype in subtypesof(fish_type))
+			if(!length(fish_safe_turfs_by_type[fish_subtype]))
+				fish_safe_turfs_by_type[fish_subtype] = fish_safe_turfs_by_type[fish_type]
+
 	return SS_INIT_SUCCESS