Predict DestructibleSystem Part 2: First batch of entity effects (#41039)

* first batch

* fix name

* fix

Content.Shared/EntityEffects/EntityEffectEvent.cs

@@ -0,0 +1,27 @@
+namespace Content.Shared.EntityEffects;
+
+/// <summary>
+/// An Event carrying an entity effect.
+/// </summary>
+/// <param name="Effect">The Effect</param>
+/// <param name="Scale">A strength scalar for the effect, defaults to 1 and typically only goes under for incomplete reactions.</param>
+/// <param name="User">The entity causing the effect.</param>
+[ByRefEvent, Access(typeof(SharedEntityEffectsSystem))]
+public readonly record struct EntityEffectEvent<T>(T Effect, float Scale, EntityUid? User) where T : EntityEffectBase<T>
+{
+    /// <summary>
+    /// The Condition being raised in this event
+    /// </summary>
+    public readonly T Effect = Effect;
+
+    /// <summary>
+    /// The Scale modifier of this Effect.
+    /// </summary>
+    public readonly float Scale = Scale;
+
+    /// <summary>
+    /// The entity that caused this effect.
+    /// Used for admin logs and prediction purposes.
+    /// </summary>
+    public readonly EntityUid? User = User;
+}