update_appearance (#55468)

Creates update_name and update_desc
Creates the wrapper proc update_appearance to batch update_name, update_desc, and update_icon together
Less non-icon handling code in update_icon and friends
Signal hooks for things that want to change names and descriptions
99%+ of the changes in this are just from switching everything over to update_appearance from update_icon

code/modules/modular_computers/computers/machinery/modular_computer.dm

@@ -53,26 +53,25 @@
 		return FALSE
 	return (cpu.emag_act(user))
 
-/obj/machinery/modular_computer/update_icon()
-	cut_overlays()
-	icon_state = icon_state_powered
+/obj/machinery/modular_computer/update_appearance(updates)
+	. = ..()
+	set_light(cpu?.enabled ? light_strength : 0)
 
-	if(!cpu || !cpu.enabled)
+/obj/machinery/modular_computer/update_icon_state()
+	icon_state = (cpu?.enabled || (!(machine_stat & NOPOWER) && cpu?.use_power())) ? icon_state_powered : icon_state_unpowered
+	return ..()
+
+/obj/machinery/modular_computer/update_overlays()
+	. = ..()
+	if(!cpu?.enabled)
 		if (!(machine_stat & NOPOWER) && (cpu?.use_power()))
-			add_overlay(screen_icon_screensaver)
-		else
-			icon_state = icon_state_unpowered
-		set_light(0)
+			. += screen_icon_screensaver
 	else
-		set_light(light_strength)
-		if(cpu.active_program)
-			add_overlay(cpu.active_program.program_icon_state ? cpu.active_program.program_icon_state : screen_icon_state_menu)
-		else
-			add_overlay(screen_icon_state_menu)
+		. += cpu.active_program?.program_icon_state || screen_icon_state_menu
 
 	if(cpu && cpu.obj_integrity <= cpu.integrity_failure * cpu.max_integrity)
-		add_overlay("bsod")
-		add_overlay("broken")
+		. += "bsod"
+		. += "broken"
 
 /obj/machinery/modular_computer/AltClick(mob/user)
 	if(cpu)
@@ -101,13 +100,13 @@
 		if(cpu)
 			cpu.shutdown_computer(0)
 	set_machine_stat(machine_stat | NOPOWER)
-	update_icon()
+	update_appearance()
 
 // Modular computers can have battery in them, we handle power in previous proc, so prevent this from messing it up for us.
 /obj/machinery/modular_computer/power_change()
 	if(cpu?.use_power()) // If MC_CPU still has a power source, PC wouldn't go offline.
 		set_machine_stat(machine_stat & ~NOPOWER)
-		update_icon()
+		update_appearance()
 		return
 	. = ..()