Refactored fire_act (#19158)

Refactored fire_act() to be in line with TG version, removed useless
parameter, added signal, made non sleepable and forced to call parent.
Added atom_act.dm file for the various *_act procs.

code/game/objects/items/stacks/sheets/leather.dm

@@ -114,7 +114,7 @@
 //Step two - washing..... it's actually in washing machine code.
 
 //Step three - drying
-/obj/item/stack/material/animalhide/wetleather/fire_act(datum/gas_mixture/air, exposed_temperature, exposed_volume)
+/obj/item/stack/material/animalhide/wetleather/fire_act(exposed_temperature, exposed_volume)
 	..()
 	if(exposed_temperature >= drying_threshold_temperature)
 		wetness--

code/game/objects/items/toys.dm

@@ -170,7 +170,9 @@
 /obj/item/toy/balloon/bullet_act()
 	burst()
 
-/obj/item/toy/balloon/fire_act(datum/gas_mixture/air, temperature, volume)
+/obj/item/toy/balloon/fire_act(temperature, volume)
+	. = ..()
+
 	if(temperature > T0C+100)
 		burst()
 	return

code/game/objects/items/weapons/grenades/dynamite.dm

@@ -57,6 +57,8 @@
 	if(!active)
 		prime()
 
-/obj/item/grenade/dynamite/fire_act()
+/obj/item/grenade/dynamite/fire_act(exposed_temperature, exposed_volume)
+	. = ..()
+
 	if(!active)
 		prime()

code/game/objects/items/weapons/tools.dm

@@ -944,7 +944,9 @@
 			to_chat(user, SPAN_WARNING("The cell isn't charged!"))
 		return TRUE
 
-/obj/item/steelwool/fire_act()
+/obj/item/steelwool/fire_act(exposed_temperature, exposed_volume)
+	. = ..()
+
 	ignite()
 
 /obj/item/steelwool/proc/ignite(var/L, mob/user)