Refactor guard bell (#1553)

* Remove maps edits

* fix from review

* Remove unused CP14 alert levels (fixing YAML)

* fix missing prototype CP14GuardBell

* fix from review 2

* fix TriggerSystem partial

---------

Co-authored-by: Jordan FUMA <@jfa>

Content.Server/_CP14/Explosion/EntitySystems/CP14TriggerSystem.Damage.cs

@@ -0,0 +1,20 @@
+using Content.Server.Explosion.Components;
+using Content.Shared.Damage;
+
+namespace Content.Server.Explosion.EntitySystems;
+
+public sealed partial class TriggerSystem
+{
+    private void InitializeDamageReceived()
+    {
+        SubscribeLocalEvent<CP14TriggerOnDamageReceivedComponent, DamageChangedEvent>(OnDamageReceived);
+    }
+
+    private void OnDamageReceived(EntityUid uid, CP14TriggerOnDamageReceivedComponent component, DamageChangedEvent args)
+    {
+        if (!args.DamageIncreased)
+            return;
+
+        Trigger(uid);
+    }
+}