[Quest API] Add GetLeader() and GetLeaderName() to Perl/Lua. (#2701)

* [Quest API] Add $raid->GetLeader() and $raid->GetLeaderName()

* Remove semicolon

* Tweaks

* Remove inline

* Add LUA compatibility

* Add GetLeaderName() to LUA

* Cast leadername to string

* Fix GetLeaderName return type

* Tweak

zone/lua_raid.h

@@ -40,6 +40,8 @@ public:
 	void BalanceHP(int penalty, uint32 group_id);
 	bool IsLeader(const char *c);
 	bool IsLeader(Lua_Client c);
+	Lua_Client GetLeader();
+	std::string GetLeaderName();
 	bool IsGroupLeader(const char *name);
 	bool IsGroupLeader(Lua_Client c);
 	int GetHighestLevel();