[Quest API] Add RemoveAlternateCurrencyValue() to Perl/Lua (#4190)

# Perl
- Add `$client->RemoveAlternateCurrencyValue(currency_id, amount)`.

# Lua
- Add `client:RemoveAlternateCurrencyValue(currency_id, amount)`.

# Notes
- Allows operators to more easily remove alternate currencies, returns a `bool`, `false` if failed`, `true` if succeeded.
- Added `Zone::DoesAlternateCurrencyExist` that will reject setting, removing, or adding  to a currency that does not exist.

zone/zone.h

@@ -152,6 +152,7 @@ public:
 	bool IsSpecialBindLocation(const glm::vec4& location);
 	bool Process();
 	bool SaveZoneCFG();
+	bool DoesAlternateCurrencyExist(uint32 currency_id);
 
 	int GetNpcPositionUpdateDistance() const;
 	void SetNpcPositionUpdateDistance(int in_npc_position_update_distance);