Sloth's subfloor vismask adventure (#35347)

* Add a subfloor vismask

Significantly cuts down on sent entity count.

* More optimisations

* Fix command

* Fixes

* namespace cleanup

* Review

* Vismasks

* Content update

* Bandaid

* awewa

* Revert these

* reh

* Update Content.Shared/SubFloor/TrayScannerComponent.cs

---------

Co-authored-by: slarticodefast <161409025+slarticodefast@users.noreply.github.com>

Content.Server/Revenant/EntitySystems/RevenantSystem.cs

@@ -63,9 +63,16 @@ public sealed partial class RevenantSystem : EntitySystem
         SubscribeLocalEvent<RevenantComponent, StatusEffectEndedEvent>(OnStatusEnded);
         SubscribeLocalEvent<RoundEndTextAppendEvent>(_ => MakeVisible(true));
 
+        SubscribeLocalEvent<RevenantComponent, GetVisMaskEvent>(OnRevenantGetVis);
+
         InitializeAbilities();
     }
 
+    private void OnRevenantGetVis(Entity<RevenantComponent> ent, ref GetVisMaskEvent args)
+    {
+        args.VisibilityMask |= (int)VisibilityFlags.Ghost;
+    }
+
     private void OnStartup(EntityUid uid, RevenantComponent component, ComponentStartup args)
     {
         //update the icon
@@ -84,10 +91,7 @@ public sealed partial class RevenantSystem : EntitySystem
         }
 
         //ghost vision
-        if (TryComp(uid, out EyeComponent? eye))
-        {
-            _eye.SetVisibilityMask(uid, eye.VisibilityMask | (int) (VisibilityFlags.Ghost), eye);
-        }
+        _eye.RefreshVisibilityMask(uid);
     }
 
     private void OnMapInit(EntityUid uid, RevenantComponent component, MapInitEvent args)