Add api to get expedition's zone name

zone/lua_expedition.h

@@ -69,6 +69,7 @@ public:
 	int             GetSecondsRemaining();
 	std::string     GetUUID();
 	int             GetZoneID();
+	std::string     GetZoneName();
 	int             GetZoneVersion();
 	bool            HasLockout(std::string event_name);
 	bool            HasReplayLockout();