Fixes machine using power from the area it was created in, rather than using the area it is in (#23188)

* Update machine area when power_change() is called.

* Do not attempt to unregister from null powernet

* Move to wrench and update wrench_acts

* Remove accidental pseudocode

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Co-authored-by: Adrer <adrermail@gmail.com>

code/modules/power/generators/thermo_electric_generator.dm

@@ -191,7 +191,7 @@
 
 /obj/machinery/power/teg/wrench_act(mob/user, obj/item/I)
 	. = TRUE
-	if(!I.use_tool(src, user, 0, volume = I.tool_volume))
+	if(!default_unfasten_wrench(user, I, 0))
 		return
 	anchored = !anchored
 	if(!anchored)