Add isomalt to nutrients?

[CharlesNepote]

Problem

• Here is at least one example of a producer using isomalt as a nutrient: https://world.openfoodfacts.org/cgi/product.pl?type=edit&code=4002590140926
• 
• Isomalt is a polyol. Should we add it while polyols already exists?

Part of

• 🧽 Data quality (tracker) #5538