Moves camera update handling to background subsystem, (maybe) fixing lag (#92208)

## About The Pull Request

When a camera update is triggered, it is instead added to a queue on a
background subsystem

An AI entering a camera chunk which is queued to update will force the
update immediately (bypassing the queue)

While the root problem of this is, ultimately, not addressed...

<img width="554" height="58"
alt="467828777-eff3f0e5-49d6-4997-b4d7-05eff6432155"
src="https://github.com/user-attachments/assets/c2d6a5f5-d958-463e-959f-116bd0dab475"
/>

...the change will ultimately prevent update spam from consuming all of
the server's resources - instead allocating updates to the backburner in
times of high server stress (or on multi-z maps)

## Changelog

🆑 Melbert
refactor: Refactored the way camera updates are handled to hopefully
reduce some lag. Report any oddities
/🆑

code/modules/mining/lavaland/mining_loot/megafauna/the_thing.dm

@@ -118,7 +118,7 @@
 	if(AI.controlled_equipment)
 		to_chat(AI, span_warning("You are already loaded into an onboard computer!"))
 		return
-	if(!GLOB.cameranet.checkCameraVis(owner))
+	if(!SScameras.is_visible_by_cameras(owner))
 		to_chat(AI, span_warning("Target is no longer near active cameras."))
 		return
 	if(!isturf(AI.loc))