Allow for alternative ingredients in recipes

[zbigniewzolnierowicz]

We should allow users to pick alternatives for ingredients.

Story

1. I want to create a recipe that requires oil for frying (doesn't matter if it's coconut, rapeseed or peanut).
2. I create a new recipe by typing in one of the oils.
3. I enter all the alternatives I think would fit
4. The recipe gets created, the first ingredient is listed as the primary one, and the alternative ingredients are listed below.