Allow excluding individual ingredients

[szmi]

What

• In bug Properly handle gluten free oats #8804 I mentioned that some people with CD (coeliac disease) are sensitive to gluten-free oats and some are not. Also AFAIK there are people with allergies to ingredients that are not part of the main allergen list.
• This feature would allow adding an "exclude ingredients" list to food preferences. If a food has any of the ingredients in the exclude list, then this would be indicated in the match result.

Part of

• Add more ingredient analysis (tracker) #5706