Explain nutrition data

Product fields:

• nutrition_data_per: Whether it is per "serving" or "100g"
• serving_size: Entered data from packaging
• serving_quantity: Computed value in g

For each nutrient:

• _value: What was entered
• _unit: Unit of what was entered
• _100g: Amount per 100g in original unit
• _serving: Amount per serving normalised unit
• no suffix: What was entered in normalised unit
• _label: Entered label for an unknown nutrient?