Upgradeable machines. (#2675)

* Start work on upgradeable machines.

* Upgradeable machines work

* Component requirements for upgradeable machines

* Better container handling

* Remember to not push submodule updates in your PRs, kids!

* Refresh parts after building a machine.

* NetSync false

* Address some reviews, fix some bugs

* Nullable stackhelpers dependencies

* Use container helper method to delete all entities in containers

* Nullable string in AddContainer

* Better examine for machine frame and construction in general

* Machine breakage

* Nullable node

* nullable GraphPrototype

* Re-save saltern for autolathe parts

* Fix SaveLoadSave

Content.Client/GameObjects/Components/Construction/MachineFrameVisualizer.cs

@@ -0,0 +1,23 @@
+using Content.Shared.GameObjects.Components.Construction;
+using JetBrains.Annotations;
+using Robust.Client.GameObjects;
+using Robust.Client.Interfaces.GameObjects.Components;
+
+namespace Content.Client.GameObjects.Components.Construction
+{
+    [UsedImplicitly]
+    public class MachineFrameVisualizer : AppearanceVisualizer
+    {
+        public override void OnChangeData(AppearanceComponent component)
+        {
+            base.OnChangeData(component);
+
+            if (component.TryGetData<int>(MachineFrameVisuals.State, out var data))
+            {
+                var sprite = component.Owner.GetComponent<ISpriteComponent>();
+
+                sprite.LayerSetState(0, $"box_{data}");
+            }
+        }
+    }
+}