[Zone] Zone State Automated Testing and Improvements (#4808)

* [Zone] Zone State Automated Testing and Improvements

* Spawn condition

* Update zone.cpp

* Remove redundant logic

* Update zone_state.cpp

* TestZLocationDrift

* Protect NPC resumed NPC's from being able to die

zone/entity.h

@@ -580,6 +580,7 @@ public:
 
 	void SendMerchantEnd(Mob* merchant);
 	void SendMerchantInventory(Mob* m, int32 slot_id = -1, bool is_delete = false);
+	void RestoreCorpse(NPC* npc, uint32_t decay_time);
 
 protected:
 	friend class Zone;