[Bug Fix] Fix GetLeaderName() for Groups (#4184)

* [Bug Fix] Fix GetLeaderName() for Groups

# Notes
- We were getting bogus data in this.
- Made it its own method.

* Remove ExpeditionRequest::GetGroupLeaderName()

zone/groups.h

@@ -76,7 +76,7 @@ public:
 	void	SplitMoney(uint32 copper, uint32 silver, uint32 gold, uint32 platinum, Client *splitter = nullptr);
 	inline	void SetLeader(Mob* c){ leader = c; };
 	inline	Mob* GetLeader() { return leader; };
-	const char*	GetLeaderName() { return GetGroupLeaderName(GetID()).c_str(); };
+	std::string	GetLeaderName();
 	void	SendHPManaEndPacketsTo(Mob* newmember);
 	void	SendHPPacketsFrom(Mob* member);
 	void	SendManaPacketFrom(Mob* member);
@@ -177,8 +177,6 @@ private:
 	int mentor_percent;
 
 	XTargetAutoHaters m_autohatermgr;
-
-	std::string GetGroupLeaderName(uint32 group_id);
 };
 
 #endif