The disposals pushing and pulling update (#1875)

* Add collision to disposal unit and pipes
Make disposal unit and pipes pullable
Implement proper handling of collisions in disposals

* Implement IsExiting
Move DisposalSystem to shared

* Change SharedDisosalUnitComponent to call manager.ContainsEntity directly

* Update saltern.yml

Co-authored-by: Julian Giebel <j.giebel@netrocks.info>

Content.Server/GameObjects/Components/Disposal/DisposalTubeComponent.cs

@@ -24,7 +24,6 @@ using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Disposal
 {
-    // TODO: Make unanchored pipes pullable
     public abstract class DisposalTubeComponent : Component, IDisposalTubeComponent, IBreakAct
     {
         [Dependency] private readonly IGameTiming _gameTiming = default!;
@@ -182,6 +181,8 @@ namespace Content.Server.GameObjects.Components.Disposal
                 return;
             }
 
+            collidable.CanCollide = !collidable.Anchored;
+
             if (collidable.Anchored)
             {
                 OnAnchor();
@@ -220,6 +221,8 @@ namespace Content.Server.GameObjects.Components.Disposal
             var collidable = Owner.EnsureComponent<CollidableComponent>();
 
             collidable.AnchoredChanged += AnchoredChanged;
+
+            collidable.CanCollide = !collidable.Anchored;
         }
 
         protected override void Startup()