Implement a Recipe class for storing ingredients in a recipe

[dcolli23]

Description

We need to create a recipe class for storing all of the ingredients in a recipe and also tallying up nutrition information for that recipe.

Proposal

The Recipe class should have the following members (this isn't necessarily an exhaustive list but includes the most important ones):

• [x] ingredients (map with the FDC ID as the key and the ingredient object pointer as the value)
  • This may change. I'm not certain this is the best approach.
• [x] ingredient_amounts (map with FDC ID as the key and a measurement struct or class as the value).
  • See #31 for details on the measurement struct or class.
• [x] serving (measurement class or struct)
  • This should most likely be in grams since that's the easiest for me to measure with a kitchen scale.
• [ ] calories_per_serving (double)
• [ ] net_carbs_g_per_serving (double)
• [ ] protein_g_per_serving (double)
• [ ] fat_g_per_serving (double)
• [x] date_of_creation (time_t)
  • See this link
• [x] rating (int)
  • Out of 5 stars.
• [x] instructions (string)
  • Instructions on how to prepare the recipe.

I'm not certain if the storage of macros is the best approach. I'm thinking we store macros for quick access and we simply iterate through the ingredients map to tally up micronutrients. Might change this approach in the future, though.

[dcolli23]

I opted to not store the macros and instead have just a map for all nutrients.