Per-map parallax support (#9786)

* Per-map parallax support

* Comments for future sloth

* c

* bet

* Fix exception

* VV support

* Fix parallax

* mem

* weightless sounds

* Gravity stuff

* placeholder coz im too lazy to stash don't @ me son

* decent clouds

* sky

* Fast parallax

* Imagine spelling

* Loicense

* perish

* Fix weightless status

Co-authored-by: metalgearsloth <metalgearsloth@gmail.com>

Content.Shared/Movement/Systems/SharedMoverController.Footsteps.cs

@@ -0,0 +1,35 @@
+using Content.Shared.Movement.Components;
+using Content.Shared.Sound;
+using Robust.Shared.GameStates;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Movement.Systems;
+
+public abstract partial class SharedMoverController
+{
+    private void InitializeFootsteps()
+    {
+        SubscribeLocalEvent<FootstepModifierComponent, ComponentGetState>(OnFootGetState);
+        SubscribeLocalEvent<FootstepModifierComponent, ComponentHandleState>(OnFootHandleState);
+    }
+
+    private void OnFootHandleState(EntityUid uid, FootstepModifierComponent component, ref ComponentHandleState args)
+    {
+        if (args.Current is not FootstepModifierComponentState state) return;
+        component.Sound = state.Sound;
+    }
+
+    private void OnFootGetState(EntityUid uid, FootstepModifierComponent component, ref ComponentGetState args)
+    {
+        args.State = new FootstepModifierComponentState()
+        {
+            Sound = component.Sound,
+        };
+    }
+
+    [Serializable, NetSerializable]
+    private sealed class FootstepModifierComponentState : ComponentState
+    {
+        public SoundSpecifier Sound = default!;
+    }
+}