Refactors is_hot and fixes some issues from the beaker lighting PR (#22964)

* Idk what I'm doing

* The is_hot refactor

* Fixes that I forgot to push before making the PR

* Update code/game/objects/items.dm

Co-authored-by: Burzah <116982774+Burzah@users.noreply.github.com>

* Contra review

* TODO: Find out why this isn't working

* Removes the signal stuff for now, this works

* Fixes it all

* Add new signal

* Update code/_onclick/item_attack.dm

Co-authored-by: Contrabang <91113370+Contrabang@users.noreply.github.com>

* Contra reivew

* Ayyy it works

* Merge master

* Forgot this one

* Update code/game/machinery/doors/airlock_types.dm

Co-authored-by: Burzah <116982774+Burzah@users.noreply.github.com>

* Update code/game/objects/structures/mineral_doors.dm

Co-authored-by: Burzah <116982774+Burzah@users.noreply.github.com>

* Update code/game/turfs/simulated/floor/mineral_floors.dm

Co-authored-by: Burzah <116982774+Burzah@users.noreply.github.com>

* Update code/game/turfs/simulated/walls_mineral.dm

Co-authored-by: Burzah <116982774+Burzah@users.noreply.github.com>

---------

Co-authored-by: Burzah <116982774+Burzah@users.noreply.github.com>
Co-authored-by: Contrabang <91113370+Contrabang@users.noreply.github.com>

code/modules/hydroponics/grown/towercap.dm

@@ -137,7 +137,7 @@
 		to_chat(user, "<span class='italics'>You add a rod to [src].")
 		var/image/U = image(icon='icons/obj/hydroponics/equipment.dmi',icon_state="bonfire_rod",pixel_y=16)
 		underlays += U
-	if(is_hot(W))
+	if(W.get_heat())
 		lighter = user.ckey
 		user.create_log(MISC_LOG, "lit a bonfire", src)
 		StartBurning()