add dataclasses

[diegoac2]

• Learn about BaseModels with Nested Data Structures and add examples
• Learn how pydantic handles
  • data validation
  • data serialization
  • data documentation, etc.

[navarroc]

For this task, talk to @vnarah2 and consider looking at the MyFarm definition he and Michal have been working on for Farmdoc. I think we're going to need a Farm/Field definition for this project so that might be a good one to try to migrate to our service using pydantic/sqlalchemy. My suggestion would be to:

1. Migrate the Farm/Field definition from Farmdoc
2. Add a service endpoint to get/post a new farm/field