Adds barotrauma (pressure damage) (#1605)

* Adds barotrauma, disables it for now

* At least show status effect, but don't damage the mobs

* Fix switch misuse

Content.Server/GameObjects/EntitySystems/BarotraumaSystem.cs

@@ -0,0 +1,29 @@
+using Content.Server.GameObjects.Components.Atmos;
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects.Systems;
+
+namespace Content.Server.GameObjects.EntitySystems
+{
+    [UsedImplicitly]
+    public class BarotraumaSystem : EntitySystem
+    {
+        private const float TimePerUpdate = 0.5f;
+
+        private float _timer = 0f;
+
+        /// <inheritdoc />
+        public override void Update(float frameTime)
+        {
+            _timer += frameTime;
+
+            if (_timer < TimePerUpdate) return;
+
+            _timer = 0f;
+
+            foreach (var barotraumaComp in ComponentManager.EntityQuery<BarotraumaComponent>())
+            {
+                barotraumaComp.Update(frameTime);
+            }
+        }
+    }
+}