Add MovementSound (#31313)

Mainly useful for medicalborg so you can get a looping sound and not footsteps playing over and over.

Didn't actually update medborg because footsteps need updating.

Not needed for AI.

Content.Shared/Movement/Components/MovementSoundComponent.cs

@@ -0,0 +1,20 @@
+using Robust.Shared.Audio;
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.Movement.Components;
+
+/// <summary>
+/// Plays a sound whenever InputMover is running.
+/// </summary>
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState]
+public sealed partial class MovementSoundComponent : Component
+{
+    /// <summary>
+    /// Sound to play when InputMover has inputs.
+    /// </summary>
+    [DataField(required: true), AutoNetworkedField]
+    public SoundSpecifier? Sound;
+
+    [DataField, AutoNetworkedField]
+    public EntityUid? SoundEntity;
+}