Moves buckling and vehicles to shared, some cleanup (#15923)

Content.Shared/Vehicle/Components/RiderComponent.cs

@@ -1,19 +1,25 @@
 using Robust.Shared.GameStates;
+using Robust.Shared.Serialization;
 
-namespace Content.Shared.Vehicle.Components
+namespace Content.Shared.Vehicle.Components;
+
+/// <summary>
+/// Added to people when they are riding in a vehicle
+/// used mostly to keep track of them for entityquery.
+/// </summary>
+[RegisterComponent, NetworkedComponent]
+public sealed class RiderComponent : Component
 {
     /// <summary>
-    /// Added to people when they are riding in a vehicle
-    /// used mostly to keep track of them for entityquery.
+    /// The vehicle this rider is currently riding.
     /// </summary>
-    [RegisterComponent, NetworkedComponent]
-    public sealed class RiderComponent : Component
-    {
-        /// <summary>
-        /// The vehicle this rider is currently riding.
-        /// </summary>
-        [ViewVariables] public EntityUid? Vehicle;
+    [ViewVariables] public EntityUid? Vehicle;
 
-        public override bool SendOnlyToOwner => true;
-    }
+    public override bool SendOnlyToOwner => true;
+}
+
+[Serializable, NetSerializable]
+public sealed class RiderComponentState : ComponentState
+{
+    public EntityUid? Entity;
 }