Ambient sound system (#4552)

* Ambient sound system

Client-side system that plays audio from nearby objects that are randomly sampled.

* Decent

* Tweaks

* Tweaks

* Comment this out for now

* reduce VM sound

* Fix rolloff

* Fixes

* Volume tweak

Content.Server/Audio/AmbientOnPoweredComponent.cs

@@ -0,0 +1,14 @@
+using Content.Shared.Audio;
+using Robust.Shared.GameObjects;
+
+namespace Content.Server.Audio
+{
+    /// <summary>
+    /// Toggles <see cref="AmbientSoundComponent"/> on when powered and off when not powered.
+    /// </summary>
+    [RegisterComponent]
+    public class AmbientOnPoweredComponent : Component
+    {
+        public override string Name => "AmbientOnPowered";
+    }
+}

Content.Server/Audio/AmbientSoundSystem.cs

@@ -0,0 +1,23 @@
+using Content.Server.Power.Components;
+using Content.Shared.Audio;
+using Robust.Shared.GameObjects;
+
+namespace Content.Server.Audio
+{
+    public sealed class AmbientSoundSystem : SharedAmbientSoundSystem
+    {
+        public override void Initialize()
+        {
+            base.Initialize();
+            SubscribeLocalEvent<AmbientOnPoweredComponent, PowerChangedEvent>(HandlePowerChange);
+        }
+
+        private void HandlePowerChange(EntityUid uid, AmbientOnPoweredComponent component, PowerChangedEvent args)
+        {
+            if (!ComponentManager.TryGetComponent<AmbientSoundComponent>(uid, out var ambientSound)) return;
+            if (ambientSound.Enabled == args.Powered) return;
+            ambientSound.Enabled = args.Powered;
+            ambientSound.Dirty();
+        }
+    }
+}