raml -> openapi
The RAML library was broken. Gitlab CI tests still passed because we built a docker image, but building this image anew resulted in broken tests because of the abandoned abao project.
This change replaces the l1ce.raml API spec with l1ce.yaml (OpenAPI 3). This restores API testing functionality. Furthermore, the L1CE now also hosts live API documentation on /docs/openapi.
Also, the API code itself can potentially be greatly reduced when we use openapi-backend