Ability to scan barcode of items already in list 

It'd be great if we could scan packaging of something we've just eaten or will throw away to help find it so we can delete it


Currently it's a nightmare trying to find items that are in the list already unless they're expired/soon to expire.

There's currently a request to filter/search list items by string #232. But just being able to scan the barcode and delete would be even easier.