Feature Request: Instead of just exposing the crud endpoints, can it generate the actual methods in a file? #216

Idea is to utilize piccolo FastAPIWrapper to generate both router files and service/repository files for the basic crud actions on a table.
Reference: https://docs.nestjs.com/recipes/crud-generator

Advantages:

1. It can then be easy to override logic based on one's use cases.
2. The generated method can then be called from other services directly instead of relying only on a HTTP call
3. Useful to scaffold a larger fastapi project with minimal effort.

BTW, I have been already enjoying working with piccolo with its many awesome features. Thanks a lot.