Add destructible component threshold triggers (#3080)

* WIP changes

* Fix tests, merge conflict and trigger once behavior

* Update yml

* Change test strings to be consts

* Fix total damage types and classes triggers

* Simplify damage trigger logic, move state to Threshold

* Update outdated code and docs

* Change the name of IBehavior back to IThresholdBehavior

* Change human gibbing to trigger at 400 brute damage

* Change gibbing from brute to blunt damage

* Fix one (1) typo

* Add damage class trigger test

* Add missing nullable enable to thresholds

Content.Server/GameObjects/Components/Destructible/Thresholds/Triggers/TotalDamageClassesTrigger.cs

@@ -0,0 +1,47 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using Content.Server.GameObjects.EntitySystems;
+using Content.Shared.Damage;
+using Content.Shared.GameObjects.Components.Damage;
+using Robust.Shared.Serialization;
+
+namespace Content.Server.GameObjects.Components.Destructible.Thresholds.Triggers
+{
+    /// <summary>
+    ///     A trigger that will activate when all of the damage classes received
+    ///     are above the specified threshold.
+    /// </summary>
+    [Serializable]
+    public class TotalDamageClassesTrigger : IThresholdTrigger
+    {
+        /// <summary>
+        ///     The amount of damage at which this threshold will trigger.
+        ///     The damage requirements of all <see cref="DamageClass"/> must be met.
+        /// </summary>
+        private Dictionary<DamageClass, int> Damage { get; set; } = new();
+
+        public void ExposeData(ObjectSerializer serializer)
+        {
+            serializer.DataField(this, x => x.Damage, "damage", new Dictionary<DamageClass, int>());
+        }
+
+        public bool Reached(IDamageableComponent damageable, DestructibleSystem system)
+        {
+            foreach (var (type, damageRequired) in Damage)
+            {
+                if (!damageable.TryGetDamage(type, out var damageReceived))
+                {
+                    return false;
+                }
+
+                if (damageReceived < damageRequired)
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+    }
+}