[Commands] Add #show special_abilities (#4043)

* [Commands] Add #show special_abilities

# Notes
- Allows operators to see what special abilities an NPC has.
- Move special ability values to `common/emu_constants.h`.
- Add `EQ::constants::GetSpecialAbilityMap()` and `EQ::constants::GetSpecialAbilityName()`.
- Add `NPC::DescribeSpecialAbilities(client)` to describe special abilities to a specified client.

# Images

* Update npc.cpp

zone/npc.h

@@ -369,6 +369,8 @@ public:
 	inline bool			IsGuarding() const { return(m_GuardPoint.w != 0); }
 	void				SaveGuardSpotCharm();
 
+	void DescribeSpecialAbilities(Client* c);
+
 	uint16 GetMeleeTexture1() const;
 	uint16 GetMeleeTexture2() const;