Refactor Item collections for thread safety and performance

Replaces static Item.ItemList and related collections with thread-safe data structures using ConcurrentDictionary and ImmutableHashSet. Adds thread-safe helpers for marking items for deconstruction and managing item lists. Updates all usages of Item.ItemList and DeconstructItems to use new APIs, improving performance and safety in multi-threaded contexts. Also refactors MeleeWeapon and Projectile impact queues to use ConcurrentQueue, and updates related logic throughout the codebase.

Barotrauma/BarotraumaShared/SharedSource/Items/Components/Projectile.cs

@@ -5,6 +5,7 @@ using FarseerPhysics.Dynamics.Contacts;
 using FarseerPhysics.Dynamics.Joints;
 using Microsoft.Xna.Framework;
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;
@@ -72,7 +73,7 @@ namespace Barotrauma.Items.Components
 
         public const float WaterDragCoefficient = 0.1f;
 
-        private readonly Queue<Impact> impactQueue = new Queue<Impact>();
+        private readonly ConcurrentQueue<Impact> impactQueue = new ConcurrentQueue<Impact>();
 
         private bool removePending;
 
@@ -840,9 +841,8 @@ namespace Barotrauma.Items.Components
                     DisableProjectileCollisions();
                 }
             }
-            while (impactQueue.Count > 0)
+            while (impactQueue.TryDequeue(out var impact))
             {
-                var impact = impactQueue.Dequeue();
                 HandleProjectileCollision(impact.Fixture, impact.Normal, impact.LinearVelocity);
             }