Add OrmliteConfig.OnModelDefinitionInit

Author: mythz

src/ServiceStack.OrmLite/ModelDefinition.cs

@@ -167,6 +167,8 @@ public void AfterInit()
             var allItems = new List<FieldDefinition>(FieldDefinitions);
             allItems.AddRange(IgnoredFieldDefinitions);
             AllFieldDefinitionsArray = allItems.ToArray();
+
+            OrmLiteConfig.OnModelDefinitionInit?.Invoke(this);
         }
 
         public bool IsRefField(FieldDefinition fieldDef)

src/ServiceStack.OrmLite/OrmLiteConfig.cs

@@ -197,5 +197,7 @@ public static IOrmLiteExecFilter ExecFilter
         public static bool SkipForeignKeys { get; set; }
 
         public static Func<string, string> ParamNameFilter { get; set; }
+        
+        public static Action<ModelDefinition> OnModelDefinitionInit { get; set; }
     }
 }