[Quest API] Add GetClassPlural() and GetRacePlural() to Perl/Lua (#3468)

* [Quest API] Add GetClassPlural() and GetRacePlural() to Perl/Lua

# Perl
- Add `$mob->GetClassPlural()`.
- Add `$mob->GetRacePlural()`.

# Lua
- Add `mob:GetClassPlural()`.
- Add `mob:GetRacePlural()`.

# Notes
- Allows operators to get the plural of a player class or race, example being `Warrior` as `Warriors` or `Dark Elf` as `Dark Elves`.

* Update mob.cpp

zone/lua_mob.h

@@ -554,6 +554,8 @@ public:
 	Lua_Mob_List GetCloseMobList();
 	Lua_Mob_List GetCloseMobList(float distance);
 	Lua_Mob_List GetCloseMobList(float distance, bool ignore_self);
+	std::string GetClassPlural();
+	std::string GetRacePlural();
 };
 
 #endif