//Search for Copies of the Item by relevant parameters
//Excluding the ISBN, which is unique for each Item
private void btnQuantity_Click(object sender, RoutedEventArgs e)
{
//Get the Item to search for from the DataGrid
AbstractItem item = (AbstractItem)dataLib.SelectedItem;
//Show the result of the Message Box
GuiMsgs.Info($"The quantity of this {item.ItemType} is {mainLibrary.ItemQuantity(item)}");
}