Engine Entity Anchoring Changes (#4195)

* Converted all SnapGridPositionChangedEvent subscriptions to AnchorStateChangedEvent.

* Fixes power tests with new anchored requirements.

* Moved AnchorableComponent into construction.
AnchorableComponent now uses Transform.Anchored.

* Fixed bug with nodes, power works again.

* Adds lifetime stages to Component.

* Update Engine to v0.4.70.

Content.Server/Atmos/Components/GridAtmosphereComponent.cs

@@ -203,7 +203,7 @@ namespace Content.Server.Atmos.Components
             _tiles = tiles;
         }
 
-        public override void Initialize()
+        protected override void Initialize()
         {
             base.Initialize();
 
@@ -234,7 +234,7 @@ namespace Content.Server.Atmos.Components
             RepopulateTiles();
         }
 
-        public override void OnAdd()
+        protected override void OnAdd()
         {
             base.OnAdd();