Swordsman Item Usage Check in Battle - isUsableItem_ATSwordman Function

This function is checking if the item at the specified index can be used by a Swordsman job in a battle situation. If the player is not currently in battle, it calls the 'isUsableItem_AllGrowJob()' function to check if the item can be used by any job class. If the player is in battle, it calls the 'isUsableItem_Quickitembar()' function to check if the item is in the quick item bar and can be used. It then returns true if the item is usable or false if it is not.