Adds tool to extract the model design

[benthomasson]

No description provided.

[cutwater]

@benthomasson I struggle to understand the purpose of this. Can you please explain what problem we're trying to solve by generating yaml definitions from the database schema?

[benthomasson]

@cutwater this allows me to generate diagrams like this:

[benthomasson]

We can also use this data to generate tests and validate that the implementation matches the design.

[ddonahue007]

lgtm

I believe tooling like this an be helpful for design and reference. I use Pycharm's Database tooling which does something very similar if not the same.