Refactored the machinery operable procs (#19274)

Refactored the machinery operable procs into a single one, DMDoc'd, SDMM
marked, made more readable.
Fixed suspension field generator not being able to be used as it was not
checking the power cell for operability.

Fixes #19249

code/modules/atmospherics/components/binary_devices/oxyregenerator.dm

@@ -96,7 +96,7 @@
 
 /obj/machinery/atmospherics/binary/oxyregenerator/process()
 	. = ..()
-	if((inoperable()) || !use_power)
+	if((!operable()) || !use_power)
 		return
 
 	var/power_draw = -1

code/modules/holodeck/HolodeckControl.dm

@@ -204,7 +204,7 @@ GLOBAL_LIST_EMPTY_TYPED(holodeck_controls, /obj/machinery/computer/holodeck_cont
 				holographic_mobs -= P
 				P.derez()
 
-	if(inoperable())
+	if(!operable())
 		return
 	if(active)
 		use_power_oneoff(item_power_usage * (holographic_objs.len + holographic_mobs.len))

code/modules/overmap/ships/computers/ship.dm

@@ -113,7 +113,7 @@ somewhere on that shuttle. Subtypes of these can be then used to perform ship ov
 		return FALSE
 
 	var/flags = issilicon(user) ? USE_ALLOW_NON_ADJACENT : 0
-	if (use_check_and_message(user, flags) || user.blinded || inoperable() || !linked)
+	if (use_check_and_message(user, flags) || user.blinded || !operable() || !linked)
 		return -1
 	else
 		return SEE_THRU

code/modules/power/apc.dm

@@ -921,7 +921,7 @@
 	return wires.is_cut(wireIndex)
 
 /obj/machinery/power/apc/proc/can_use(mob/user, var/loud = 0) //used by attack_hand() and Topic()
-	if(inoperable())
+	if(!operable())
 		return FALSE
 	var/use_flags = issilicon(user) && USE_ALLOW_NON_ADJACENT // AIs and borgs can use it at range
 	use_flags |= (check_rights(R_ADMIN, FALSE, user) && USE_ALLOW_NONLIVING) // admins can use the UI when ghosting

code/modules/power/fusion/fuel_assembly/fuel_injector.dm

@@ -29,7 +29,7 @@
 
 /obj/machinery/fusion_fuel_injector/process()
 	if(injecting)
-		if(inoperable())
+		if(!operable())
 			StopInjecting()
 		else
 			Inject()

code/modules/power/fusion/kinetic_harvester.dm

@@ -95,7 +95,7 @@
 			harvesting.Cut()
 
 /obj/machinery/kinetic_harvester/update_icon()
-	if(inoperable())
+	if(!operable())
 		icon_state = "broken"
 	else if(use_power >= POWER_USE_ACTIVE)
 		icon_state = "on"

code/modules/reagents/Chemistry-Machinery.dm

@@ -312,7 +312,7 @@
 	return src.attack_hand(user)
 
 /obj/machinery/chem_master/attack_hand(mob/user as mob)
-	if(inoperable())
+	if(!operable())
 		return
 	user.set_machine(src)
 	ui_interact(user)
@@ -428,7 +428,7 @@
 	interact(user)
 
 /obj/machinery/reagentgrinder/interact(mob/user as mob) // The microwave Menu
-	if(inoperable())
+	if(!operable())
 		return
 	user.set_machine(src)
 	var/is_chamber_empty = 0

code/modules/research/xenoarchaeology/tools/suspension_generator.dm

@@ -38,6 +38,14 @@
 
 	ui_interact(user)
 
+/obj/machinery/suspension_gen/operable(additional_flags)
+	if(stat & (BROKEN|additional_flags))
+		return FALSE
+	if(!cell.charge)
+		return FALSE
+
+	return TRUE
+
 /obj/machinery/suspension_gen/attackby(obj/item/attacking_item, mob/user)
 	if(attacking_item.isscrewdriver())
 		if(!open)