Reworks how AI tracking is handled & reorganizes it (#77776)

## About The Pull Request

Completely reworks how AI tracking is handled, this has no in-game
effects.
This moves nearly all AI tracking handling onto ``/datum/tracking``,
which previously was pretty bad. I tried documenting as much as I can,
making comments actually useful and give accurate information.

Turns ``get_camera_list`` into a global proc, which we now use for
camera consoles (including the app), cutting down on copy paste in 2
areas and standardizing its behavior/backend.

## Why It's Good For The Game

I wanted to generalize this behavior so I can use it for tracking
players in https://github.com/tgstation/tgstation/pull/77713 - This
helps me do that.
Also the current state of AI tracking code is pretty poor and hopefully
this improves that area.

Closes https://github.com/tgstation/tgstation/issues/42355

## Changelog

🆑
refactor: AI's player-tracking eyes received an unwanted obligatory
update, and should now not tell you that a player is untrackable when
they clearly obviously can be.
/🆑

code/modules/modular_computers/file_system/programs/secureye.dm

@@ -86,7 +86,7 @@
 /datum/computer_file/program/secureye/ui_static_data(mob/user)
 	var/list/data = list()
 	data["mapRef"] = cam_screen.assigned_map
-	var/list/cameras = get_available_cameras()
+	var/list/cameras = get_camera_list(network)
 	data["cameras"] = list()
 	for(var/i in cameras)
 		var/obj/machinery/camera/C = cameras[i]
@@ -102,7 +102,7 @@
 		return
 	if(action == "switch_camera")
 		var/c_tag = format_text(params["name"])
-		var/list/cameras = get_available_cameras()
+		var/list/cameras = get_camera_list(network)
 		var/obj/machinery/camera/selected_camera = cameras[c_tag]
 		camera_ref = WEAKREF(selected_camera)
 		playsound(src, get_sfx(SFX_TERMINAL_TYPE), 25, FALSE)
@@ -168,26 +168,4 @@
 	cam_background.icon_state = "scanline2"
 	cam_background.fill_rect(1, 1, DEFAULT_MAP_SIZE, DEFAULT_MAP_SIZE)
 
-// Returns the list of cameras accessible from this computer
-/datum/computer_file/program/secureye/proc/get_available_cameras()
-	var/list/L = list()
-	for (var/obj/machinery/camera/cam as anything in GLOB.cameranet.cameras)
-		//Get the camera's turf in case it's inside something like a borg
-		var/turf/camera_turf = get_turf(cam)
-		if(!is_station_level(camera_turf.z))//Only show station cameras.
-			continue
-		L.Add(cam)
-	var/list/camlist = list()
-	for(var/obj/machinery/camera/cam in L)
-		if(!cam.network)
-			stack_trace("Camera in a cameranet has no camera network")
-			continue
-		if(!(islist(cam.network)))
-			stack_trace("Camera in a cameranet has a non-list camera network")
-			continue
-		var/list/tempnetwork = cam.network & network
-		if(tempnetwork.len)
-			camlist["[cam.c_tag]"] = cam
-	return camlist
-
 #undef DEFAULT_MAP_SIZE