Add tests to do proper contract testing 
Currently the e2e tests use the OpenAPI spec to do some contract testing, but it's not extensive.

The idea is to cover most of, or all, the cases documented in the OpenAPI spec.
Add tests to do proper contract testing : Currently the e2e tests use the OpenAPI spec to do some contract testing, but it's not extensive.

The idea is to cover most of, or all, the cases documented in the OpenAPI spec.