Puddles & spreader refactor (#15191)

Content.Shared/Movement/Events/GetFootstepSoundEvent.cs

@@ -0,0 +1,17 @@
+using Robust.Shared.Audio;
+
+namespace Content.Shared.Movement.Events;
+
+/// <summary>
+/// Raised directed on an entity when trying to get a relevant footstep sound
+/// </summary>
+[ByRefEvent]
+public record struct GetFootstepSoundEvent(EntityUid User)
+{
+    public readonly EntityUid User = User;
+
+    /// <summary>
+    /// Set the sound to specify a footstep sound and mark as handled.
+    /// </summary>
+    public SoundSpecifier? Sound;
+}