Adds the antimatter engine (#1905)

* adds antimatter engine

* fixes some nullables

* fixes ALL OF THE NULLABLES

* adds explosions

* adds fancy lighting

* requested changes + license info

Co-authored-by: ancientpower <ancientpowerer@gmail.com>

Content.Server/GameObjects/Components/NodeContainer/NodeGroups/NodeGroupFactory.cs

@@ -62,6 +62,7 @@ namespace Content.Server.GameObjects.Components.NodeContainer.NodeGroups
         HVPower,
         MVPower,
         Apc,
+        AMEngine,
         Pipe,
     }
 }