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.Shared/Light/EntitySystems/SlimPoweredLightSystem.cs

@@ -0,0 +1,67 @@
+using Content.Shared.Light.Components;
+using Content.Shared.Power;
+using Content.Shared.Power.Components;
+using Content.Shared.Power.EntitySystems;
+
+namespace Content.Shared.Light.EntitySystems;
+
+public sealed class SlimPoweredLightSystem : EntitySystem
+{
+    [Dependency] private readonly SharedPowerReceiverSystem _receiver = default!;
+    [Dependency] private readonly SharedPointLightSystem _lights = default!;
+
+    private bool _setting;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeLocalEvent<SlimPoweredLightComponent, AttemptPointLightToggleEvent>(OnLightAttempt);
+        SubscribeLocalEvent<SlimPoweredLightComponent, PowerChangedEvent>(OnLightPowerChanged);
+    }
+
+    private void OnLightAttempt(Entity<SlimPoweredLightComponent> ent, ref AttemptPointLightToggleEvent args)
+    {
+        // Early-out to avoid having to trycomp stuff if we're the caller setting it
+        if (_setting)
+            return;
+
+        if (args.Enabled && !_receiver.IsPowered(ent.Owner))
+            args.Cancelled = true;
+    }
+
+    private void OnLightPowerChanged(Entity<SlimPoweredLightComponent> ent, ref PowerChangedEvent args)
+    {
+        // Early out if we don't need to trycomp.
+        if (args.Powered)
+        {
+            if (!ent.Comp.Enabled)
+                return;
+        }
+        else
+        {
+            if (!ent.Comp.Enabled)
+                return;
+        }
+
+        if (!_lights.TryGetLight(ent.Owner, out var light))
+            return;
+
+        var enabled = ent.Comp.Enabled && args.Powered;
+        _setting = true;
+        _lights.SetEnabled(ent.Owner, enabled, light);
+        _setting = false;
+    }
+
+    public void SetEnabled(Entity<SlimPoweredLightComponent?> entity, bool enabled)
+    {
+        if (!Resolve(entity.Owner, ref entity.Comp, false))
+            return;
+
+        if (entity.Comp.Enabled == enabled)
+            return;
+
+        entity.Comp.Enabled = enabled;
+        Dirty(entity);
+        _lights.SetEnabled(entity.Owner, enabled);
+    }
+}