Power stuff (#31314)

* Power stuff

- Add shared IsPowered
- Add shared ResolveApc
- Move PowerChangedEvent to shared for now
- Add SlimPoweredLight that actually functions how you'd expect a PoweredLight to function it id didn't have a bunch of bloat on it.

* big update

* boing

Content.Server/Temperature/Systems/EntityHeaterSystem.cs

@@ -3,6 +3,7 @@ using Content.Server.Temperature.Components;
 using Content.Shared.Examine;
 using Content.Shared.Placeable;
 using Content.Shared.Popups;
+using Content.Shared.Power;
 using Content.Shared.Temperature;
 using Content.Shared.Verbs;
 using Robust.Server.Audio;