EntityButton no longer inherits PanelContainer.

It didn't use the functionality so.

Content.Client/GameObjects/Components/Storage/ClientStorageComponent.cs

@@ -284,7 +284,7 @@ namespace Content.Client.GameObjects.Components.Storage
         /// <summary>
         /// Button created for each entity that represents that item in the storage UI, with a texture, and name and size label
         /// </summary>
-        private class EntityButton : PanelContainer
+        private class EntityButton : Control
         {
             public EntityUid EntityUid { get; set; }
             public Button ActualButton { get; }