[Feature Request] Add item ID support for Extra Items Bar

[YetAnotherDevWannabe]

WT in really awesome so first thanks and congratulation for this gem.
One thing that would make it even better IMO would be to support adding items by ID directly to an extra item bar instead of using the groups you have.

I'm an Alchemist so the FLASKDF is overloaded with every stupid phial blizz thought people wanted in every quality, so no really usable.
But I also have the same problem with POTIONDF for pots and I can have 2 custom lists.

Hence if we could directly add item IDs of the items we want would be S tier :D