Fix conveyor mispredicts (#28157)

* Fix conveyor mispredicts

Instead of tracking active conveyors we instead track the conveyed entities. This also handles things like stacking conveyors more gracely.

* Fix ActiveConveyor

* Fix lerping

Content.Server/Physics/Controllers/ConveyorController.cs

@@ -55,8 +55,6 @@ public sealed class ConveyorController : SharedConveyorController
         if (MetaData(uid).EntityLifeStage >= EntityLifeStage.Terminating)
             return;
 
-        RemComp<ActiveConveyorComponent>(uid);
-
         if (!TryComp<PhysicsComponent>(uid, out var physics))
             return;