Valid schema for "/steering/api/v1/playout" endpoint

Parent: [EPIC] Future-proof AURA API (aura#192)

Currently returned object does not provide valid OpenApi Schema implementation.

For now I manually built a client model with some workaround. It would be important, if this could be replaced with some official Steering interface.

Also consider Generate virtual timeslots for unscheduled cale... (#120 - closed). The final API schema should be thought together, or be extended when Virtual Timeslots are fully implemented.

Related

During the implementation of engine#129 (closed) I realized the endpoint /steering/api/v1/playout is not defined in the API spec. This should be covered by Refactor Steering API endpoints currently not i... (#210 - closed)