[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/mob.h

@@ -1331,6 +1331,9 @@ public:
 
 	bool HasSpellEffect(int effect_id);
 
+	std::string GetRacePlural();
+	std::string GetClassPlural();
+
 	//Command #Tune functions
 	void TuneGetStats(Mob* defender, Mob *attacker);
 	void TuneGetACByPctMitigation(Mob* defender, Mob *attacker, float pct_mitigation, int interval = 10, int max_loop = 1000, int atk_override = 0, int Msg = 0);