Nodes - Avoid overriding paths pointing to unloaded plugins with empty values

Nodes  - Store the type of paths so that node connections can be restored even if the path their types are based on are unavailable

src/Artemis.Storage/Entities/Profile/DataModelPathEntity.cs

@@ -4,4 +4,5 @@ public class DataModelPathEntity
 {
     public string Path { get; set; }
     public string DataModelId { get; set; }
+    public string Type { get; set; }
 }