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/game/objects/items/devices/multitool.dm

@@ -95,10 +95,6 @@
 /obj/item/multitool/ai_detect/proc/multitool_detect()
 	var/turf/our_turf = get_turf(src)
 	detect_state = PROXIMITY_NONE
-	for(var/mob/living/silicon/ai/AI as anything in GLOB.ai_list)
-		if(AI.cameraFollow == src)
-			detect_state = PROXIMITY_ON_SCREEN
-			return
 
 	for(var/mob/camera/ai_eye/AI_eye as anything in GLOB.aiEyes)
 		if(!AI_eye.ai_detector_visible)