refactor(Core/InstanceScript): refactored load and save methods (#14977)

Co-authored-by: joschiwald <736792+joschiwald@users.noreply.github.com>

src/server/scripts/EasternKingdoms/ZulAman/instance_zulaman.cpp

@@ -91,6 +91,7 @@ public:
 
         void Initialize() override
         {
+            SetHeaders(DataHeader);
             memset(&m_auiEncounter, 0, sizeof(m_auiEncounter));
 
             QuestTimer = 0;

src/server/scripts/EasternKingdoms/ZulAman/zulaman.h

@@ -20,6 +20,7 @@
 
 #include "CreatureAIImpl.h"
 
+#define DataHeader "ZA"
 #define ZulAmanScriptName "instance_zulaman"
 
 enum DataTypes