TriggerSystem improvements (#35762)

* desynchronizer real

* yaml stuff from slarti branch

* C# stuff

* oops

* fix triggers

* atomize PR

---------

Co-authored-by: Flareguy <woaj9999@outlook.com>

Content.Server/Polymorph/Systems/PolymorphSystem.Trigger.cs

@@ -0,0 +1,41 @@
+using Content.Shared.Polymorph;
+using Content.Server.Polymorph.Components;
+using Content.Server.Explosion.EntitySystems;
+using Robust.Shared.Prototypes;
+
+namespace Content.Server.Polymorph.Systems;
+
+public sealed partial class PolymorphSystem
+{
+    /// <summary>
+    /// Need to do this so we don't get a collection enumeration error in physics by polymorphing
+    /// an entity we're colliding with in case of TriggerOnCollide.
+    /// Also makes sure other trigger effects don't activate in nullspace after we have polymorphed.
+    /// </summary>
+    private Queue<(EntityUid Ent, ProtoId<PolymorphPrototype> Polymorph)> _queuedPolymorphUpdates = new();
+
+    private void InitializeTrigger()
+    {
+        SubscribeLocalEvent<PolymorphOnTriggerComponent, TriggerEvent>(OnTrigger);
+    }
+
+    private void OnTrigger(Entity<PolymorphOnTriggerComponent> ent, ref TriggerEvent args)
+    {
+        if (args.User == null)
+            return;
+
+        _queuedPolymorphUpdates.Enqueue((args.User.Value, ent.Comp.Polymorph));
+        args.Handled = true;
+    }
+
+    public void UpdateTrigger()
+    {
+        while (_queuedPolymorphUpdates.TryDequeue(out var data))
+        {
+            if (TerminatingOrDeleted(data.Item1))
+                continue;
+
+            PolymorphEntity(data.Item1, data.Item2);
+        }
+    }
+}