[Bug Fix] Fix Item Discovery (#4663)

* [Bug Fix] Fix Item Discovery for Pickups, Evolving, Fishing, and Forage

* Push

* Caching

* Update tradeskills.cpp

* Update task_client_state.cpp

zone/zone.h

@@ -241,6 +241,8 @@ public:
 
 	std::unordered_map<uint32, EXPModifier> exp_modifiers;
 
+	std::vector<uint32> discovered_items;
+
 	time_t weather_timer;
 	Timer  spawn2_timer;
 	Timer  hot_reload_timer;