Core/ScriptMgr: Replace IsDatabaseBound() methods through traits.

(cherry picked from commit 12d1993994b11785174c7caa7d7f9b5aa87d8411)

src/server/game/Scripting/ScriptMgr.cpp

@@ -41,6 +41,60 @@
     UnusedScriptNamesContainer UnusedScriptNames;
 // }
 
+// Trait which indicates whether this script type
+// must be assigned in the database.
+template<typename>
+struct is_script_database_bound
+    : std::false_type { };
+
+template<>
+struct is_script_database_bound<SpellScriptLoader>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<InstanceMapScript>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<ItemScript>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<CreatureScript>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<GameObjectScript>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<AreaTriggerScript>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<BattlegroundScript>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<OutdoorPvPScript>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<WeatherScript>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<ConditionScript>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<TransportScript>
+    : std::true_type { };
+
+template<>
+struct is_script_database_bound<AchievementCriteriaScript>
+    : std::true_type { };
+
 // This is the global static registry of scripts.
 template<class TScript>
 class ScriptRegistry
@@ -71,7 +125,7 @@ class ScriptRegistry
                 }
             }
 
-            if (script->IsDatabaseBound())
+            if (is_script_database_bound<TScript>::value)
             {
                 // Get an ID for the script. An ID only exists if it's a script that is assigned in the database
                 // through a script name (or similar).