feat(Core): Achievements (#47)

Achievements

src/LuaEngine/Hooks.h

@@ -206,6 +206,7 @@ namespace Hooks
         PLAYER_EVENT_ON_COMMAND                 =     42,       // (event, player, command, chatHandler) - player is nil if command used from console. Can return false
         PLAYER_EVENT_ON_PET_ADDED_TO_WORLD      =     43,       // (event, player, pet)
         PLAYER_EVENT_ON_LEARN_SPELL             =     44,       // (event, player, spellId)
+        PLAYER_EVENT_ON_ACHIEVEMENT_COMPLETE    =     45,       // (event, player, achievement)
 
         PLAYER_EVENT_COUNT
     };