Remove IRadiationAct (#7757)

* Move radiation collector to ECS

* Damagable system

* Remove IRadiationAct

* Add small helper field

* Update Content.Server/Radiation/Systems/RadiationSystem.cs

Co-authored-by: Leon Friedrich <60421075+ElectroJr@users.noreply.github.com>

* Delete comment

* Fixed total rads

Co-authored-by: Leon Friedrich <60421075+ElectroJr@users.noreply.github.com>

Content.Shared/Radiation/Events/OnIrradiatedEvent.cs

@@ -0,0 +1,20 @@
+namespace Content.Shared.Radiation.Events;
+
+/// <summary>
+///     Raised on entity when it was irradiated
+///     by some radiation source.
+/// </summary>
+public sealed class OnIrradiatedEvent : EntityEventArgs
+{
+    public readonly float FrameTime;
+
+    public readonly float RadsPerSecond;
+
+    public float TotalRads => RadsPerSecond * FrameTime;
+
+    public OnIrradiatedEvent(float frameTime, float radsPerSecond)
+    {
+        FrameTime = frameTime;
+        RadsPerSecond = radsPerSecond;
+    }
+}