feat: add property based testing

[eoaksnes]

To automatically test the API using FastAPI’s self-generated OpenAPI specification using schemathesis.

Schemathesis works by looking at the API specification and automatically generating test cases for each endpoint.

Schemathesis checks whether your API is accepting and returning payloads with the right shape and types, whether it handles URL query and path parameters correctly, whether it returns the right status codes, and more.

By leveraging property-based testing, schemathesis is capable of generating thousands of test cases for your API