Enforces specific order in nutrition keys and adds reorder script

[jknndy]

Attempt at a solution to conversation related to nutrition key order in #1197

test_nutrition_order.py

• Adds a test to check the order of nested nutrient keys against order listed on Schema NutritionInformation
• Handles non-schema designated nutrient keys by expecting them to exist below ordered schema designated keys.

scripts/reorder_nutrition_keys.py

• Adds a new helper script to reorder nutrition keys
• Order designated by Schema NutritionInformation page
• Appends extra non-schema designated nutrient keys below ordered schema designated in no particular order.

test_data

• Reordered 171 nutrients tests

see woop.json for example of nutrients outside the schema designations.

[jknndy]

• Refactored the nutrition_keys list into a method
• Updated the reorder script accordingly and refactored to only iterate through each JSON once
• Test updates
• Added a new util test for get_nutrition_keys